Salesforce Platform Developer I (2025) – Comprehensive Study Guide

Exam Outline and Structure

The Salesforce Certified Platform Developer I exam consists of 60 multiple-choice/multiple-select questions, with a passing score of 68%. You are given 105 minutes to complete the exam. There are no official prerequisite certifications, though foundational knowledge (e.g. Admin and App Builder skills) is highly recommended. The exam content is divided into four sections (objectives) with the following weightings:

• Developer Fundamentals – 23%

• Process Automation & Logic – 30% (highest weight)

• User Interface – 25%

• Testing, Debugging & Deployment – 22%

Each section is detailed below with an overview of key topics, hands-on practice suggestions, critical concepts for flashcards, and study strategies. Higher-weighted sections (e.g. Process Automation & Logic) warrant proportionally more study time, as they represent a larger portion of the exam.

However, do not neglect any section – a balanced understanding of all topics is essential to reach the ~68% passing threshold. Use this guide to focus your learning, practice actively on Trailhead, and reinforce knowledge through flashcards and repetition.

Developer Fundamentals (23%)

Overview: This section covers core architectural concepts and declarative vs. programmatic fundamentals on the Salesforce platform. Start with Salesforce’s multi-tenant architecture: Salesforce runs on a multi-tenant cloud, meaning many customers share the same infrastructure and application resources. To ensure fairness, Salesforce enforces governor limits (restrictions on CPU, queries, DML, etc.) so that no single tenant can monopolize resources. For example, if a transaction exceeds certain limits (like too many queries or too much CPU time), a runtime exception (e.g. a LimitException) will occur to stop it. Multi-tenancy also means all customers are on the same version of Salesforce; updates are pushed automatically three times a year (Spring, Summer, Winter releases) with no manual upgrades. Trust and security are paramount in this model – even though hardware and code are shared, each org’s data is isolated and secure, and every org benefits from the platform’s reliability, security, and new features with each release.

Another fundamental is the MVC design pattern and how Salesforce’s platform features map to it. In Salesforce’s interpretation of Model-View-Controller (MVC), the Model represents the data and schema (e.g. standard and custom objects, fields, relationships, and even Apex classes as business logic containers). The View is the user interface – think of page layouts, Lightning pages, Visualforce pages, and Lightning Web Components (all the components and pages that display data to the user). The Controller is the business logic that interacts with the model and dictates what the view displays – this includes Apex code (classes, triggers) and even declarative logic like process automation that responds to user input or data changes. Understanding MVC helps to conceptualize how different pieces of Salesforce (database, UI, logic) work together in a governed, multi-tenant environment.

Salesforce provides two main approaches for building customizations: declarative (no-code) and programmatic (code). A key skill is knowing when to use declarative tools vs. programmatic solutions in a given scenario. Declarative tools (clicks-not-code) include things like Formula Fields and Roll-Up Summary Fields (for read-only calculations), validation rules, Lightning Flow (Process Builder/Workflow and Flow Builder for automation), and others. These are often faster to build and easier to maintain. Programmatic solutions involve Apex code, triggers, Visualforce, or Lightning components – used for more complex requirements that declarative tools can’t satisfy. Best practice is to use declarative features as much as possible (for example, a roll-up summary field to summarize child data, instead of writing an Apex trigger) and only resort to Apex or custom code for requirements that can’t be met declaratively. This not only reduces maintenance burden but also leverages Salesforce’s optimizations – declarative features are generally “governor limit aware” and scale well. An exam scenario might ask which approach is best (declarative vs. code) for a given requirement, so be familiar with common use-cases: e.g., use a formula field for a simple calculation on a record, use roll-up summary fields on a master-detail to aggregate child data, use Flow or Process Builder for routine automation (field updates, email alerts, record creation), but use Apex code for complex validations, custom integrations, or transaction control that declarative tools can’t handle.

Data modeling is another critical fundamental. You should be able to design an appropriate data model given a set of requirements – this means deciding what objects are needed (standard or custom), what fields, and especially what types of relationships to use between objects. Salesforce offers relationship types like Lookup and Master-Detail. A Lookup relationship loosely links two objects – the child can exist without the parent and does not inherit parent’s sharing or deletion (if you delete a lookup parent, the child record remains, just with its lookup field cleared). A Master-Detail relationship tightly links objects – the child (detail) record inherits ownership and security from the parent (master), and if you delete the master, all its detail records are also deleted (cascade delete). Master-detail allows additional features like roll-up summary fields on the master to aggregate detail data. You should also understand Many-to-Many relationships, which are implemented in Salesforce by using a third object called a junction object with two master-detail fields (allowing each junction record to link one instance of each of the two objects, enabling many-to-many connectivity). Additionally, be aware of External relationships (External Lookup and Indirect Lookup) which link Salesforce records to external data (for instance, linking a Salesforce object to an external object record via an external ID). An External ID is a flag on a field (often a text/number field) that marks it as a unique record identifier from an outside system – external IDs are used to match and upsert data. They let you load or integrate data by an alternate key instead of the Salesforce record Id. For example, when using the API or Data Loader, you can upsert records using an external ID field to decide insert vs. update. Make sure you grasp the implications of schema design: changing field types or object relationships can have impact on existing Apex code and integrations (e.g. a master-detail conversion might require adding required parents to all child records, or changing a text field to number could break Apex code expecting text).

Finally, importing and exporting data is part of this section. Know the common tools and considerations for moving data in or out of Salesforce, especially in development and test environments. For small data loads (<50K records), the Data Import Wizard (built-in to Setup) is convenient but limited to certain standard objects and simple mappings. For larger or more complex data loads, Data Loader is a go-to tool; it can import, update, upsert using external IDs, or export records and handles up to 5 million records. Be mindful of how these tools trigger automation: both will fire Apex triggers, workflows, flows, etc. unless those are deliberately disabled in the target org. When exporting data, consider tools like Data Loader (or the SOQL export in Developer Console or Workbench) and understand the format (CSV) and the need to preserve record IDs for relationships. In a development context (like sandboxes or scratch orgs), you might use sandbox refreshes, sandbox seeding, or the Salesforce CLI with source and data commands to migrate sample data. Also, remember that when using Change Sets or metadata deployments, data isn’t moved – only metadata. If an exam scenario asks how to move configuration vs. how to move data sample records, be sure you choose the appropriate mechanism.

Hands-On Practice (Trailhead & Exercises):

• Trailhead Module: Understand the Salesforce Architecture – Provides a friendly overview of multitenancy, metadata-driven platform, and API basics. This will reinforce multi-tenant concepts and why governor limits and trust are important.

• Trailhead Module: Data Modeling – Practice creating custom objects and relationships. Focus on scenarios of when to use lookup vs master-detail. For instance, create a simple app with a Project__c object and Task__c detail records to see how roll-up summaries work.

• Trailhead Module: Platform Developer I Certification Prep: Salesforce Fundamentals & Data Modeling – This is an official prep module covering multi-tenancy, MVC, data model design, and import/export considerations. Complete the quizzes and hands-on challenges to test your understanding.

• DIY Exercise: In a Developer Edition org or Trailhead Playground, try designing a mini schema: for example, Library and Book objects with different relationship types. Implement a master-detail (Library–Book) and observe how deleting a library deletes its books. Then change it to a lookup to see the difference in behavior. Also practice using the Data Import Wizard to load some Book records (e.g. from a CSV) and use Data Loader to export them, getting comfortable with each tool.

• Trailhead Projects/Superbadges: The App Customization Specialist Superbadge (or similar Admin superbadges) can be useful here – they involve building data models, fields, and security, which solidify fundamental platform knowledge.

Key Concepts for Flashcards: (Use these to drill yourself – define each term and understand its significance.)

• Multitenant Architecture: A single, shared infrastructure where all customers’ orgs run on the same platform instance, with isolated data. Enforced by governor limits to ensure fair use.

• Governor Limits: Limits on resource usage in Salesforce (e.g. 100 SOQL queries per transaction, 50,000 records query return limit, 150 DML statements per transaction) that prevent any one process from over-consuming shared resources. Example: You can retrieve at most 50,000 records in total via SOQL in a single transaction – more will throw a LimitException.

• MVC Pattern – Model: The data layer (sObjects, fields, relationships, metadata). View: The UI layer (pages, components, Lightning pages, Visualforce). Controller: The logic layer (Apex controllers, triggers, or declarative logic like flows and rules). Be able to cite Salesforce examples of each.

• Lightning Component Framework: Modern UI framework for building single-page apps in SF. Includes Aura Components and Lightning Web Components (LWC). Key benefits: client-side JS for rich interactivity and server-side Apex for data, with an event-driven architecture for communication.

• Declarative vs. Programmatic: Know examples of declarative tools (Flow, process builder, formulas, roll-ups) and when they’re sufficient, versus when to use Apex code. Flashcard prompt: “When should you prefer a declarative solution over Apex?” (Answer: When out-of-the-box features can meet requirements, since they are easier to maintain and less error-prone – use Apex only for scenarios that cannot be achieved declaratively).

• Roll-Up Summary Field: A field on a master object that aggregates data from its detail records (count, sum, etc.) – only available for master-detail relationships. No coding needed, but cannot be used on lookup relationships.

• External ID: A field marked as a unique identifier for external data. Often used for upsert operations and integrations to match records by an external system’s ID. Note: External IDs improve performance when upserting (acts like a key/index) and can be used in SOQL queries ([SELECT ... FROM Account WHERE External_Id__c = 'XYZ']).

• Data Loader vs. Import Wizard: Data Loader can handle up to millions of records and supports insert, update, delete, upsert, export. Import Wizard is limited to 50k records and insert/update (no export or complex relationships). Typical exam question: When to use one over the other (e.g. “How to load 100k new records with an external ID for matching?” → Data Loader).

• AppExchange: (Still useful to know) The marketplace for pre-built apps and components. Common scenario: When to build vs. buy? If a requirement is common (e.g. document generation), you might get an AppExchange package rather than coding from scratch.

Exam Focus Tips: This section carries ~23% of the exam, so roughly 14 out of 60 questions. Many fundamentals concepts tie into other sections (for example, understanding data model and declarative features underpins Process Automation & Logic questions). If you have an Admin/App Builder background, you may find some of these questions straightforward (e.g. identifying a master-detail vs lookup use-case, or knowing what a roll-up summary can do). Don’t skip studying this section, but if you’re strong here, you can prioritize extra time on the heavier coding sections. Focus on memorizing terminology and “why/when” knowledge: Why multi-tenancy imposes limits, when to choose one relationship type or solution over another. These lend themselves well to flashcards and quick concept checks. Aim to be comfortable with Salesforce data modeling scenarios and the basic platform architecture, as this creates a foundation for understanding the deeper development topics.

Process Automation & Logic (30%)

Overview: This is the largest and arguably most important section – ~30% of the exam – focusing on Apex programming, declarative automation, and the nuts and bolts of business logic on the platform. A significant portion of questions will test your understanding of Apex code (the Salesforce proprietary programming language similar to Java) and how/when to use it in conjunction with or instead of declarative tools. Expect scenario-based questions about triggers, classes, and automation design.

Start with declarative process automation features: ensure you know the capabilities of Workflow Rules, Process Builder, and Flows (note: Workflow and Process Builder are legacy at this point, and Flow is the go-forward automation tool, but the exam may reference them historically). For example, Workflow can do simple field updates or send emails (single if/then logic), Process Builder can do multiple if/then branches and create records or invoke Apex, and Flow Builder can handle more complex logic, loops, and even screens for user input. Understand the limits: e.g., flows can now do most things that required code in the past. However, there are times when declarative automation might not be enough – such as complex looping over thousands of records (which might hit flow limits) or integrating with external systems – and that’s where Apex comes in. When to use declarative vs. triggers is a common decision point: the exam may give a scenario like “on update of an Account, do X on related Contacts” – this can be done with a record-triggered Flow or an Apex trigger. Since Salesforce encourages “low-code” solutions, if a declarative approach can do it, it’s often the correct choice, but you should also consider maintainability and governor limits.

Next, dive into Apex language basics. You need to know how to declare variables and constants, use Apex data types, and write simple expressions. Key Apex data types include primitives (Integer, String, Boolean, Decimal, etc.), collections (List, Set, Map), sObjects (standard and custom objects as types), and more complex types like Apex classes and enums. Understand the syntax for loops and control flow: if-else statements, for loops (including the special SOQL-for loop), and while loops. Also know how to write methods and use access modifiers (public, private, global, protected) and keywords like with sharing/without sharing (which control record-level security in Apex code). Apex also supports interfaces and inheritance – for the exam, you should at least grasp what an interface is (a template of methods that a class can implement) and a typical use case (Salesforce has built-in interfaces like Database.Batchable, Schedulable that you implement to run batch or scheduled jobs). The exam may include a question like “given this interface and class, what is the outcome when executed” or a question on the implications of using with sharing.

A large chunk of this section is about writing and understanding Apex Triggers and Classes. Know how to write a basic trigger, including the context variables (like Trigger.new, Trigger.old, Trigger.isInsert, etc.). Trigger bulkification is paramount: Salesforce triggers fire per batch of 200 records by default, so Apex code must handle collections of records efficiently. This means using for loops and collections instead of singleton operations. Best practice is to avoid SOQL or DML inside loops; instead, query or process data in sets to stay within limits. For example, if updating child records when a parent changes, one would gather all child IDs and do one SOQL query, rather than querying inside a loop for each parent. Expect questions on what a piece of trigger code does, or identifying why a given trigger is failing (often due to not handling bulk updates or recursion). One trigger per object is a recommended design (using logic in helper classes if needed) – while the exam might not explicitly test that pattern, it might implicitly in a scenario about controlling trigger execution order (since if you have multiple triggers on the same object event, their execution order is indeterminate). Also, understand the order of execution in a save transaction (the sequence of events when a record is saved: before triggers, after triggers, workflow rules, processes, escalation rules, etc., and how recursion could happen). Knowing the order of execution is crucial for troubleshooting why a certain outcome is occurring (e.g. a validation rule firing after a before trigger, etc.).

In Apex, you must also know how to work with SOQL and SOSL queries and DML statements. SOQL (Salesforce Object Query Language) is like SQL: e.g. SELECT Id, Name FROM Account WHERE Name = 'Acme'. You should know how to write a SOQL query in Apex and the basics of querying child records or parent fields via relationships. SOSL (Salesforce Object Search Language) is a text search that can query across multiple objects at once (for example, find all records containing “Acme” in name or phone). Key differences: SOQL returns records in an ordered structure and is used when you know which object(s) and fields to query; SOSL returns lists of lists of sObjects (because it can search multiple objects) and is used for broad searches (like a global search). DML statements in Apex include insert, update, upsert, delete, undelete. Understand that DML can also be done in bulk (e.g. inserting a List<Account>). The exam might test a code snippet and ask for the outcome, including whether it will compile or throw an error – e.g. trying to update a list that was queried read-only in a for-loop might throw a “List has no rows for assignment” or attempting DML on a list that contains both valid and invalid records might result in partial success if using Database.insert(records, false) vs. insert records which is all-or-none.

Governor limits are frequently tested in this section. You should memorize key limits and understand their impact on design. For instance: 100 SOQL queries per transaction (synchronous) – if you exceed this, you get a runtime exception. 50,000 records retrieved total by SOQL per transaction – exceeding that yields a LimitException. 150 DML statements per transaction (so batch your record changes into at most 150 operations). Other notable limits: 20 SOSL queries per transaction, 100 callouts per transaction, 6 MB synchronous Apex heap size, 10,000 rows processed by DML operations in a transaction, etc. You cannot catch LimitExceptions with try-catch (they will always halt execution when a governor limit is hit). Instead, you must design your code to avoid hitting limits (e.g. bulkify queries, use batch Apex for large data operations). Flashcards on these numbers are useful: a question might simply ask “What is the maximum number of SOQL queries allowed in a single Apex transaction?” or present a scenario and you have to know which limit is violated.

Another topic is the relationship between Apex transactions and the save order of execution. This includes understanding how before triggers can modify field values before the record is saved, how after triggers can query additional data or make changes that require the record ID, and how one trigger firing can cause other records’ triggers to fire (cascade) or recursively trigger itself (for example, if an after update trigger updates another record of the same object type, it can re-fire triggers on that object). Salesforce has protections to prevent infinite recursion (there’s a limit on trigger depth of 16 and on future calls, etc.), but you are expected to know strategies to avoid unwanted recursion – e.g. using static variables to ensure a trigger only runs once on the same set of records. Also know that each trigger execution is part of a single transaction, and all DML either succeeds or is rolled back if an uncaught exception occurs.

Exception handling in Apex is another key area. You should know how to use try-catch-finally blocks to handle errors, and when to throw exceptions. Salesforce has a hierarchy of exception types (like DmlException, NullPointerException, QueryException, etc.). Be aware of which exceptions you can catch and which you cannot (for example, you cannot catch LimitException governor limit errors in your code). The exam may ask which exception type would be thrown in a given scenario, or what happens if an exception is not caught (it bubbles up and rolls back the transaction). Also, custom exceptions can be created by extending Exception class – you might see a question about when to use a custom exception (e.g. to create a specific error type for business logic errors and throw it to caller). A typical scenario is using try-catch around a callout or DML and then throwing a custom exception or returning an error.

Finally, understand how declarative and programmatic automation can work together. A common example is using an Invocable Method (an Apex method annotated with @InvocableMethod) that can be called from a Flow, combining code with Flow for advanced logic. Another is having a trigger that does part of the work and a workflow field update that does another part – although it’s generally better to do all related logic in one place, some scenarios intentionally mix for flexibility. Recognize that if you have both a Process and a Trigger on the same object event, both will execute – the order of execution will run the trigger first (before and after), then the process (after save, since processes fire after triggers in the save order). For exam prep, know that you can use Apex to fill gaps in Flows (via invocable actions) and use Flows to orchestrate logic without writing an entire trigger from scratch.

Hands-On Practice (Trailhead & Exercises):

• Trailhead Module: Apex Basics & Variables – This teaches Apex syntax, how to declare variables, data types, and write simple Apex code. Practice writing basic classes and triggers in your dev org, even a “Hello World” trigger on a Contact that sets a field value.

• Trailhead Module: Apex Triggers – Walks through trigger scenarios and best practices (bulkification, context variables). Make sure to do the exercises, like creating a trigger that updates a parent field when children change.

• Trailhead Module: SOQL and SOSL – (e.g. “SOQL for Admins” or “Apex Basics & Database” modules) to practice writing queries. In a Playground org, try queries in the Developer Console’s Query Editor to get familiar with syntax. Then try writing equivalent queries in an Apex class and iterating over results.

• Superbadge: Apex Specialist Superbadge – This is a more involved challenge, but if you have time, it’s extremely useful. It makes you write Apex classes, triggers, and tests for a realistic scenario. Even if you don’t complete it before the exam, attempting parts of it will expose you to typical use cases that often align with exam topics.

• Practice Apex Problems: Come up with small scenarios, e.g.: “When an Account’s rating is changed to ‘Hot’, automatically create a Task.” Try solving this first with a record-triggered Flow, then with an Apex trigger, to see both approaches. Or “Write an Apex method to find all Accounts with no Contacts” (hint: use a LEFT JOIN SOQL or aggregate query). Little exercises like these help solidify your understanding of Apex logic and governor considerations.

• Trailhead Project: Quick Start: Apex – A guided project to set up a developer environment and deploy Apex code. This can help you learn to use Developer Console and see debug logs when running code.

• Use Developer Console: Write a simple Apex class with a few methods (e.g. math operations or string manipulations) and call them using Anonymous Apex to see results. Practice using System.debug() and checking debug logs – this will also prepare you for debugging scenarios in the Testing/Debugging section.

Key Concepts for Flashcards:

• Record-Triggered Flow vs. Apex Trigger: Both can run logic on record changes. Flashcard prompt: “When should you use a Flow instead of an Apex trigger?” (Answer: If the logic can be achieved declaratively without hitting limits – e.g. small-scale or straightforward record manipulations – use Flow for ease of maintenance. Use Apex trigger for complex logic, large data volumes, or when needing transactions spanning multiple objects or custom error handling).

• Apex Data Types: Know the difference between List, Set, and Map. For example, a Set<String> avoids duplicates, a Map<Id, Account> maps Ids to Account records (useful for bulk operations). Flashcard example: “What collection type would you use to store unique Id values? (Set).”

• SOQL vs SOSL: SOQL is for structured queries (one object at a time (or with parent-child subqueries)), returns records. SOSL is for free-text search across multiple objects, returns lists of sObject lists.

• DML Options: All-or-none vs partial (Database class methods). E.g., insert accounts; (all-or-none) vs Database.insert(accounts, false) (continues on errors). Understand that partial allows successful records to commit while others fail.

• Trigger Context Variables: e.g. Trigger.new (new records in insert/update), Trigger.old (old values for update/delete), Trigger.isExecuting, Trigger.isInsert, Trigger.isAfter, etc. Flashcard: “What does Trigger.new contain in a before insert vs. before delete trigger?” (Answer: In before insert, Trigger.new contains the new records about to be saved; in before delete, Trigger.new is not available (since records are being deleted), but Trigger.old contains the records being deleted).

• Order of Execution: The sequence of events when a record is saved (before triggers → validation rules → after triggers → processes/workflows → etc., finally commit). You should be able to identify at what point certain automations fire. For instance, a common quiz: “At what point is a record assigned an ID? (After the before triggers, when the record is first saved to the database, so by the time after triggers run, the ID exists).”

• Governor Limit Values: Memorize key limits – 100 SOQL queries per transaction, 50,000 max records queried, 150 DML statements, 20 SOSL queries, 100 callouts, 10 scheduled Apex jobs at once, etc. Also 6 MB sync Apex heap, 10 seconds max SOQL run time, 10,000 records processed per DML operation (like in a Trigger.new). These make good flashcard fodder (question on one side, number on the other).

• System Mode vs User Mode: Apex generally runs in system mode (ignores user permissions and field-level security by default), except when explicitly using with sharing or certain contexts (like executing as user in flow or LWC). Visualforce controllers can run in user mode depending on the controller type (standard vs custom). Know that with sharing enforces sharing rules in Apex, whereas without sharing (default) does not.

• Exception Handling: Know at least one example of an exception that cannot be caught – e.g. LimitException (governor limits). Also know how to intentionally throw an exception (throw new CustomException('msg');) and that throwing an exception will rollback the transaction unless caught.

• Best Practices: Bulkify your code (no SOQL inside loops!), use collections. Avoid hardcoding IDs or values (use Custom Settings/Metadata or describe calls). Use “one trigger per object” principle and delegate logic to handler classes. Use test-driven development (which ties into Testing section).

Exam Focus Tips: This is the highest-weight section (30%), which means roughly 18 questions. A strong performance here is critical to passing. It’s also the section that tends to be most challenging for those new to coding, so allocate significant study time to practicing Apex and automation logic. Prioritize understanding over rote memorization – for example, rather than just memorizing trigger syntax, practice reading small Apex code snippets and predicting what they do. The exam often presents a short code block and asks for the outcome or error, testing your applied knowledge. If you find coding concepts daunting, break your study into subtopics (SOQL, triggers, Apex basics, etc.) and tackle one at a time with hands-on practice; Trailhead and sample problems are your friends. Given the weight, aim for mastery: you should reach a point where you can mentally run through an Apex snippet and catch mistakes (e.g. see a SOQL in a loop and realize it would hit limits on bulk data). Also remember, since this section is broad, don’t neglect the declarative aspects – a few questions will likely cover Flows or formulas vs. code scenarios. By focusing on this section, you build confidence for nearly one-third of the exam. Lastly, leverage flashcards for the limit numbers and terminology, but use a sandbox or Playground to actually write code for real understanding. The combination of memorization and applied practice will yield the best results here.

User Interface (25%)

Overview: This section tests your knowledge of building custom user interfaces on the Salesforce platform, including older technologies like Visualforce and newer ones like Lightning Web Components (LWC) and Aura components. It makes up about 25% of the exam, so roughly 15 questions. A key theme is knowing how to display and update data via custom UI and ensuring security on those interfaces.

First, understand Visualforce Page fundamentals. Visualforce (VF) is a framework for building custom pages, primarily for the classic UI (though VF pages can also appear in Lightning Experience). A VF page uses an HTML-like markup with Salesforce-specific tags (e.g. <apex:page>, <apex:form>, <apex:outputField>, etc.) and is served from Salesforce. Know how a Visualforce page can display Salesforce data using a controller. There are three controller types: Standard Controller (binds the page to a standard or custom object, giving you basic CRUD operations and access to a record or list of records), Custom Controller (an Apex class you write from scratch with logic for the page, not using a standard controller at all), and Controller Extension (an Apex class that extends or augments a standard controller). You should know when to use each. For instance, to make a quick page that edits a record, a standard controller might suffice. To override a standard button action with some extra logic, you might use a controller extension. To build something completely custom (say a page that pulls data from multiple objects and external web service), a custom controller is needed. The exam may present a scenario like “You need a page to display a list of related records and allow inline edit, which controller approach do you use?” – understanding the capabilities of each is key.

Also be aware of the types of content you can embed in Visualforce pages. VF can include static HTML/JavaScript, use CSS for styling, and even embed other web content via iframes or Canvas. It can also host Lightning components via Lightning Out or include an <apex:includeLightning /> tag to apply Lightning Experience styling to a VF page (by setting lightningStylesheets="true" on the <apex:page> tag, the page will use SLDS styles for a more modern look). One common use case is adding a VF page as a custom tab or override, or using VF in places where Lightning Components might not be available (e.g., a quick action in certain contexts). Although Visualforce is considered an older tech now, it is still on the test and widely used in many orgs, so don’t skip studying it. Make sure you know basic Visualforce page syntax, how to reference data ({! record.Field__c } merge expressions), and how to call Apex methods from VF (e.g. using <apex:commandButton action="{!save}" /> that calls a controller’s method).

Next, Lightning components: Salesforce has the Aura Component Framework (often just referred to as “Lightning Components” historically) and the modern Lightning Web Components (LWC). The exam outline explicitly mentions the “Lightning Component framework, its benefits, and types of content in an LWC”. Key points: The Lightning Component framework is used to build dynamic, single-page style applications for Lightning Experience. Aura components were the original model (with a component bundle containing markup, controller, helper, etc.), and Lightning Web Components are the newer model built on standard web standards (a bundle of HTML, JavaScript, and metadata files). Benefits of Lightning Components include a more interactive UX, better performance (because of client-side rendering and partial page updates), and reusability (components can be dropped into different pages or apps). LWC specifically has benefits of using native browser capabilities, which means less Salesforce-specific framework overhead and easier adoption of web standards.

Know what content can be in an LWC: since LWC uses standard web tech, you can include HTML for structure, CSS for styles (or use the Salesforce Lightning Design System classes), and JavaScript for client-side logic. You can also import Apex methods to call them imperatively or use wire adapters to get data. LWC can also utilize Pub/Sub modules for communication between components. The outline mentions “use cases and best practices for LWC events” – you should understand how components communicate: an LWC can fire a CustomEvent to send data to a parent component (this is akin to Aura component events but now using DOM events). Best practices include using events for parent-child comms, avoiding overly broad event scope (in Aura, you’d prefer component events to application events; in LWC, you might use a shared messaging service for sibling components rather than abusing the event system). Essentially, know how events propagate in LWC (they bubble up the DOM, can be stopped or composed across shadow DOM boundaries) and that you usually use a CustomEvent with a detail property to pass data. A best practice: keep event payloads small (primitives) to avoid giving child components direct references to parent data (which could be mutated unexpectedly). Also, LWC events can be configured with bubbles and composed flags – generally default events are non-bubbling and non-composed within the shadow DOM (which is safer and encapsulated). The exam might not get too low-level on this, but it could ask something conceptual like “How do two sibling LWCs communicate?” (Answer: via a parent mediator – either the parent handles an event from one and passes data to the other, or use a pub-sub module since siblings can’t directly interact without a common parent or an event bus).

The UI section also covers security in custom interfaces. This includes understanding user data access and UI security vulnerabilities. For Visualforce and Apex controllers, this means respecting CRUD/FLS (object and field-level security) – Apex running in system mode can violate these unless you enforce them manually (using Schema.sObjectType describes or with sharing for record sharing). Lightning components (Aura/LWC) run in user context for data access (meaning they typically use Apex to get data, and that Apex can be with or without sharing). The exam objective explicitly states “Given a scenario, prevent user interface and data access security vulnerabilities.” This implies you should know about common vulnerabilities like SOQL injection (and how to prevent it by binding variables or using escapeSingleQuote), Cross-Site Scripting (XSS) in Visualforce (for example, outputting user input without escaping can be dangerous; always use <apex:outputText escape="true"> by default), and avoiding exposing sensitive data on the client side. Lightning Locker (now Lightning Web Security) is Salesforce’s mechanism to isolate component namespaces, but you likely just need to know that it exists to protect components from each other. Also know that if you’re using JavaScript in LWC, the framework automatically escapes HTML output to prevent XSS in most cases. A scenario might describe a piece of code vulnerable to SOQL injection (e.g. constructing dynamic SOQL with unchecked user input) and ask what the issue is or how to fix it (by using bind variables or escaping quotes). Another might describe a Visualforce page where a query string parameter is used in the controller SOQL – to secure it, you’d sanitize or type-cast the parameter.

Finally, be familiar with how custom UI components are surfaced in Salesforce and how Apex can work with them. For example, you can put a Lightning component on a record page or in a utility bar, or use a Visualforce page in a classic app or as a Lightning Component via an iframe. The exam outline mentions displaying and using custom components including Lightning Components, Flow, and Visualforce. This suggests you should know how these can intermingle: e.g., you can launch a Flow with a custom UI (a Flow screen) from a Lightning action, or embed a Flow in a Lightning page. You can incorporate a Visualforce page in Lightning via the “Visualforce” standard component or use Lightning Out to embed Lightning components in Visualforce. Also, know about Next Best Action (now called Einstein Next Best Action) – it can render recommended actions via a component that may call Apex behind the scenes. The outline’s mention of “implement Apex to work with various types of page components (Lightning Components, Flow, Next Best Action, etc.)” means you might see a scenario like: “How would you call server-side logic from a Lightning Web Component?” and the answer is using Apex methods annotated with @AuraEnabled (so they can be cached or called) or using an Apex-invocable method for a Flow. Essentially, be comfortable with how the UI layer interacts with Apex: Aura and LWC use @AuraEnabled Apex methods (imperatively or via wire); Flows use invocable Apex or standard screen components; Visualforce uses Apex controllers and action methods.

Hands-On Practice (Trailhead & Exercises):

• Trailhead Module: Visualforce Basics – Build a simple Visualforce page and controller. For example, create a VF page that shows a list of Accounts and lets you select one to view details. This will reinforce how to use standard list controllers vs. writing SOQL in a custom controller.

• Trailhead Module: Lightning Web Components Basics – Go through the basics of LWC, create a “Hello World” LWC and deploy it to a record page. Practice passing data via @api properties and firing a simple CustomEvent (perhaps have a child LWC fire an event and a parent LWC handle it to update a message).

• Trailhead Module: Aura Components Basics – Aura is less emphasized now, but completing a basic Aura component exercise (creating a component with a controller and helper) helps you recognize Aura syntax (aura:id, components, etc.) in case it appears on the exam. Some questions might still reference Aura components or application events.

• Visualforce Exercise: Try overriding a standard action. For instance, override the “New” button of an object with a Visualforce page that has a custom form. This will teach you how VF interacts with standard controller navigation and saving. Also practice using lightningStylesheets="true" on the VF page to see how it adopts Lightning look.

• Security Practice: Intentionally introduce a vulnerability in a test Visualforce page (like outputting <script>alert('xss')</script> from a string variable) and see how using <apex:outputText escape="false"> vs escape="true" behaves. Similarly, write an Apex snippet that builds a SOQL string from user input, and then fix it by using a binding variable. This hands-on approach will solidify what not to do in terms of security.

• Trailhead Module: Lightning Aura and LWC Events – If available, find Trailhead content specifically on communication patterns between components. Otherwise, Salesforce documentation examples for LWC events are great – try to implement a parent-child LWC where the child emits an event and the parent reacts (e.g., child component has a button that when clicked, sends an event to increment a counter in the parent).

• App Builder Mix: Use the Lightning App Builder to combine components – e.g., place a flow, a visualforce page, and a custom LWC on one Lightning Home Page. This will give you a practical sense of how these pieces coexist. It’s also useful to see how you pass parameters to Visualforce via Lightning pages or how a Flow’s output could be input to a component (though mostly flows and components don’t directly feed each other without custom integration).

Key Concepts for Flashcards:

• Visualforce Standard vs Custom Controller: Standard controllers provide out-of-the-box CRUD logic for a single record or list (and come with a save() method, etc.), whereas a custom controller is an Apex class you write to define custom logic and data fetching. Flashcard prompt: “What’s the difference between a Visualforce standard controller and a custom controller?”

• Controller Extension: An Apex class that extends a standard controller’s functionality (it has a constructor taking ApexPages.StandardController as a parameter). Use this when you need to add logic to a standard controller page (e.g. a custom button that does additional processing before save).

• Lightning Web Component (LWC): A UI component model using standard web technologies (HTML, JS, CSS). Key traits: Uses the shadow DOM for encapsulation, communicates with Apex via @AuraEnabled methods, and with other components via events.

• Aura vs LWC: Aura components use a proprietary component model (with .cmp files, controllers, events), while LWC uses modern JavaScript. Both can coexist and both run in Lightning. Aura had the concept of application events vs component events – in LWC, all events are essentially component (DOM) events. Potential question: “How do you ensure two independent LWCs communicate if they are not in the same DOM hierarchy?” (One answer: use a Lightning Message Service or pub-sub pattern, which isn’t deeply covered on PD1 but good to know conceptually).

• SLDS (Styling): Salesforce Lightning Design System – a CSS framework for styling components/pages with the Lightning Experience look. You might need to know that in Visualforce you enable SLDS by adding lightningStylesheets="true" on the page, or by manually including the SLDS stylesheets.

• Security: XSS Prevention: In Visualforce, use <apex:outputText> (which escapes HTML by default) instead of outputting raw user input. In Lightning, know that data-binding in LWC is safe by default (it won’t render raw HTML unless you specifically use LWC’s dangerous HTML rendering with innerHTML, which is rare).

• Security: SOQL Injection Prevention: Never concatenate unchecked user input into dynamic SOQL strings. Instead, use bind variables or the escape methods. E.g., prefer String name = ApexPages.currentPage().getParameters().get('name'); List<Account> accts = [SELECT Id FROM Account WHERE Name = :name]; rather than building a query string.

• UI API vs Apex in UI: Although not heavily tested, be aware that standard Lightning components often use the Lightning Data Service under the hood (UI API) to fetch and save data without Apex. But custom logic or multi-object operations often require Apex.

• Lightning Events: In Aura: component event vs application event (component event is narrower scope). In LWC: use CustomEvent. Flashcard: “True or False: In LWC, you should typically use CustomEvent with detail to communicate from child to parent, and avoid global event buses unless necessary. (True).”

• Navigation: How do you expose a component or VF page? E.g., Visualforce can be a custom tab or override standard actions. LWCs can be made available in the App Builder by specifying targets (like record page, home page). Aura components can also have design files for placement. Not heavily quizzed, but you might get a question like “How can an LWC be used in a quick action?” (By configuring it as a Lightning Component Quick Action target).

Exam Focus Tips: At 25% weight, the UI section is significant. Many candidates find this section tricky if they haven’t worked with Visualforce or Aura/LWC before, because it involves different technologies. Do not underestimate Visualforce – even though it’s “old,” several exam questions often cover VF page logic or controllers. If you come from a modern LWC-focused background, brush up on Visualforce basics. Conversely, if you’re from a classic background, update yourself on LWC concepts, as the exam is updated to include LWC (e.g. understanding events, @wire, etc.). Pay attention to security best practices, as those are high-yield and often straightforward points if memorized (e.g. knowing that a certain code snippet is vulnerable to SOQL injection is an easy question if you’ve seen it before). For preparation, prioritize Visualforce and Apex controller interactions and LWC basics. Aura components appear less, but a general awareness can’t hurt (maybe 1 question). Because this section has a lot of different pieces (VF, Aura, LWC, security, UI API), consider making a small chart or mind map of UI technologies and their key points to visually organize the info. In terms of study allocation, if you’re not strong in front-end development, spend extra time doing the hands-on exercises to solidify these concepts – seeing how a Visualforce page or LWC actually works will help the knowledge stick much more than just reading. Finally, recall that UI scenarios might tie in with Apex – for instance, a question might span UI and logic: “A Lightning component calls an Apex method to get data – how should that Apex method be declared?” (Answer: @AuraEnabled, maybe cacheable=true if just fetching data). So having integrated understanding is useful. Overall, treat this section as “applied knowledge” – visualizing how users and data interact through custom interfaces – and you’ll be able to work through the scenario-based questions effectively.

Testing, Debugging, and Deployment (22%)

Overview: This section covers the lifecycle after development: writing and running tests, debugging issues, and deploying code to different environments. It comprises about 22% of the exam (~13 questions). Though it’s the smallest section by weight, it’s still crucial – plus, mastering testing and deployment will improve your ability to deliver working solutions in practice.

Begin with Apex testing – Salesforce places heavy emphasis on test coverage and best practices. Every candidate should know that you must have at least 75% code coverage from tests to deploy Apex to production, and all triggers must have some coverage. Testing on the platform isn’t just about hitting a percentage; it’s about ensuring logic works as expected and doesn’t break in production. Know how to write an Apex test class: it’s an Apex class annotated with @isTest. Test methods are static, void, take no arguments, and have the @isTest annotation (or you can use the older testMethod keyword). You’ll often create test data within test methods (since tests run in isolation, and by default have no access to org data). Key concept: Use utility test classes or @testSetup methods to create common test records that all tests can use. Understand the testing framework requirements: tests do not commit data and roll back at the end, unless you use Test.startTest() / Test.stopTest() which are for isolating asynchronous calls and resetting governor limits within a test. The exam might include a question on the purpose of Test.startTest() and Test.stopTest() (Answer: to simulate a fresh context and to execute any enqueued async code like future methods or batch executes after stopTest). Also, know how to run tests: via Developer Console, via Salesforce CLI, or in UI (Setup > Apex Test Execution).

Be familiar with testing specific scenarios: testing triggers (usually by inserting or updating records to fire the trigger), testing future/queueable/batch (you call them like normal methods in a test, but for batch you might need to start and stop test around the Database.executeBatch), and testing callouts. For callouts, remember you must use Mock callouts (implement HttpCalloutMock interface) since tests can’t call external services. Also, know about seeAllData=true – by default it’s false, meaning tests cannot see org data. It’s best practice to leave SeeAllData false (for isolation) and create the data you need in the test. The exam might ask how to test something in a scenario: e.g., “How to test a method that performs a web service callout?” (Answer: set up a mock using Test.setMock and call Test.startTest()/stopTest() to invoke the callout which then uses the mock response).

For debugging, you should know the tools available: Debug Logs, Developer Console log inspector, and system debug statements. If an exam scenario describes an issue in production, likely the answer involves checking debug logs or using the setup audit tools. Understand log categories and levels (e.g. setting Apex code logging to DEBUG, etc.). Also, know how to debug Flow errors: when a Flow fails, Salesforce can send an email with an error, and you can also debug-run flows in Flow Builder or check the Flow Interview logs (in Setup under Flows, there's a section for Paused and Failed flow interviews). For process builders, one would typically examine debug logs as well (they show up as FLOW_ELEMENT_* entries). If a question asks “How can a developer find the cause of a process failing after deployment?”, a safe bet is “review debug logs and look for error messages or exceptions in the flow’s context”.

Also, asynchronous debugging: if dealing with Queueables, Future methods, or Batch jobs, you might use the Async Apex Job monitor and check logs for those specifically. The exam may mention “monitoring asynchronous and batch jobs” – be aware of the Apex Jobs page in Setup (which shows batch jobs, scheduled jobs, etc.), the Scheduled Jobs page for scheduled Apex, and the fact that each batch execution has its own log.

Know how to use tools like Salesforce CLI (sfdx) for deployments and how to run tests via CLI. The exam outline references “Salesforce Developer tools such as Salesforce DX, CLI, and Developer Console”. This means you should know at a high level what each is for:

• Developer Console: in-browser tool for writing/debugging Apex and running tests or SOQL queries. Good for quick diagnostics (e.g. checking debug logs, running test classes on the fly).

• Salesforce CLI (sfdx): a command-line tool for scripting deployments, data loads, creating scratch orgs, etc. Useful for continuous integration or when using source control.

• Salesforce DX (Developer Experience): not a tool per se but a set of features including scratch orgs, unlocked packaging – likely you won’t be asked deeply about packaging, but maybe know that DX encourages source-driven development in scratch orgs and uses CLI for deployments.

• Workbench: not explicitly mentioned, but sometimes used for queries or deployments in the web.

• VS Code with Salesforce Extensions: how many devs write code now, but the exam might not cover IDE specifics.

Moving to deployment: Understand the typical environments and deployment process. Know the various sandbox types (Dev, Test/QA, UAT, Full) and that you develop in sandboxes or scratch orgs and deploy to production. Deployment options include Change Sets (point-and-click, between connected orgs), Metadata API (using tools like ANT or SFDX CLI to push source), and newer options like Unlocked Packages. The exam might ask, for example, “Which deployment tool would you use to deploy metadata to a related org without manual steps?” – answer: Change Set if within same environment, or metadata API (CLI/ANT) for more control. Also remember that Apex code deployment requires all tests to run and pass (with 75% coverage overall). You might get a question about test execution on deploy: by default, all local tests (and any relevant managed package tests) run on production deployment. If a test fails, the deployment is rolled back. For large orgs, you can run a subset of tests with certain tools, but you still need 75% coverage overall.

Release management: be aware of the concept of Continuous Integration (CI) – not deeply tested, but a general knowledge that you can use source control and automated tests to ensure quality. More specific might be sandbox strategy: e.g., develop in a Dev sandbox, test in a QA sandbox, then UAT in a UAT sandbox, then deploy to Prod. Sandbox refresh intervals might come up: Developer sandboxes can refresh daily, Full copy every 29 days – maybe one question on environment choice: “Which sandbox should be used for performance testing with a copy of production data?” (Answer: Full sandbox, because it copies all data and has production-equivalent performance and a 29-day refresh cycle).

Finally, change management: The outline mentions describing environments and processes for deploying code and config. This means know how things like profiles or picklist values might need to be moved along with code. Some things are metadata (can be deployed), some are data (need to be migrated separately). An exam question might be, “You have a new custom field and Apex code referring to it – how do you deploy to production?” The answer: via a Change Set or Metadata API deployment that includes the field and the Apex, and by running tests to meet coverage. Or “What’s a necessary step to take before deploying Apex?” (Run all tests and ensure 75% coverage).

Hands-On Practice (Trailhead & Exercises):

• Trailhead Module: Apex Testing – Write test classes for Apex code you wrote in earlier sections. If you created triggers or classes, now write tests for them. Use System.assert() to verify outcomes. This module will cover key points like test data isolation and best practices.

• Trailhead Module: Debugging Apex – This will show you how to use debug logs and set debug log levels. A good exercise is to cause a known error (e.g., divide by zero in Apex) and then find it in the debug log. Practice reading a debug log from top to bottom; they can be verbose, but get a feel for locating “EXCEPTION_THROWN” or “FATAL_ERROR” lines.

• Trailhead Module: Developer Console Basics – Make sure you can navigate the Developer Console: open logs, use the Query Editor, run tests from the UI. The certification might not directly test clicking in Developer Console, but experience here will help understanding.

• CLI Exercise: If you haven’t, install Salesforce CLI and try retrieving metadata from a dev org and then deploying it to another (if you have two free dev orgs or use a scratch org). Even just retrieving the Apex classes as files on your machine and validating a deploy (with sfdx force:mdapi:deploy with the -c check only flag) will expose you to the mechanics of deployment.

• Trailhead Module: Change Set Development – If new to change sets, follow a trail or help article to create and deploy a change set between a sandbox and another org. This will underscore how profiles/permissions need to be added, etc.

• Error Scenario Drills: Write a simple Apex class with an intentional bug (like something that queries too many records in a loop). Deploy it to a sandbox and run it with a test to generate a governor limit error, then practice reading the debug log or the error email (if any). This will make you comfortable diagnosing limit errors.

• Trailhead Module: Platform Developer I Certification Prep: Testing, Debugging, and Deployment – There may be an official prep unit that recaps these topics. Use it to ensure you’ve covered everything, and answer the quizzes to test your knowledge.

Key Concepts for Flashcards:

• Test Coverage Requirement: 75% of Apex code must be covered by tests to deploy to production. Also: all tests must pass. Good to remember that test methods themselves don’t count toward the lines of code.

• @isTest and @testSetup: @isTest class is used to indicate a test class. @testSetup annotated method runs once per class to create test data that each test method can use (improves efficiency and consistency of data setup).

• System.runAs(): Used to run test code under the context of a different user (to test sharing rules or profile permissions). It doesn’t enforce field level security or permissions by itself, but it does simulate user record sharing. Note that runAs still won’t allow you to break org-wide limits (like user license limits on doing DML).

• Test.startTest()/stopTest(): Used in test methods to reset governor limits count and execute async code. Everything between start and stop is considered a new context (so you can, for example, enqueue a future method and then at stopTest, that future will run).

• Debug Log Levels: E.g., NONE, ERROR, WARN, INFO, DEBUG for Apex code logs. Knowing that you can configure what to capture (Apex, Database, Validation, Workflow, etc.) can be useful if an exam question asks “how to obtain more detailed logging for a specific area.”

• Deployment Tools: Change Sets (simple, within connected orgs, limited control), Ant/Metadata API (more flexible, scriptable, can deploy to any org given credentials), SFDX CLI (modern way to deploy via source format or metadata format, used for scratch orgs and unlocked packages). Maybe remember that Change Sets cannot be used for all metadata (e.g. you can’t deploy standard picklist values via change set easily, or you can’t move data).

• Profiles/Permission Sets in Deployments: If deploying components that require profile access (like a new field or VF page), ensure the profile settings are included or updated post-deployment. The exam might not dig in here deeply, but an awareness that deployment isn’t just code – you must consider security settings – is good.

• Continuous Integration (CI): e.g. using tools like Jenkins, GitHub Actions with the CLI to automate tests on every commit. Not likely a direct exam topic, but conceptually useful if a question asks about ensuring code quality before deployment (answer: implement a process to run all tests in a staging environment or use scratch orgs with a CI pipeline).

• Sandbox Types & Uses: Developer vs Developer Pro vs Partial vs Full – storage and refresh differences (Dev/Dev Pro daily, Partial 5 days, Full 29 days). Know that Full sandbox is needed for performance/load testing as it includes full data, whereas Developer sandbox is for unit testing and development (no data copied by default except setup and maybe template if applied).

• Error Monitoring: Besides debug logs, know about Apex Trigger Emails (if a trigger throws an uncaught exception in production, SF can send an email to admins), and tools like Lightning Exception Logs for LWC errors (these are in the Browser console rather than server logs). Possibly out of scope, but worth knowing error handling mechanisms.

Exam Focus Tips: While this section is smaller in percentage, it’s often where you can secure points with straightforward knowledge. Many questions in this domain are direct: e.g., “What must be done to deploy Apex to production?” or “How to identify the cause of a failing test?” If you study the clear-cut rules (75% coverage, seeAllData, etc.) and the purpose of each tool, you can answer confidently. Pay attention to any known Salesforce quirks: for instance, remember that deploying to production runs all tests by default (which might catch you off guard if some old test is failing – though that’s more a real-world tip). Also recall that tests do not count toward storage or leave data – a question might ask what happens after test execution (answer: data is rolled back, so it won’t persist). Time management in study: ensure you devote some time to writing test classes if you haven’t before – the act of writing a test will teach you more than reading about it. And since the exam might include one or two code snippet questions about tests, that practice will pay off. Deployment questions might be scenario-based, like choosing the right tool or sequence for deployment; think from a best-practice standpoint (e.g. deploy to a staging sandbox first, run all tests, then prod). Given the integrated nature of Salesforce, some questions here could also tie back to earlier topics (for example, a question about a piece of code failing only in production might relate to not having SeeAllData in tests or a profile missing permission after deployment). So having a holistic view helps. All in all, this section is about ensuring quality and moving changes reliably – if you prepare with that mindset, you’ll likely cover the necessary ground to pick up these points.

Final Preparation Strategies

In summary, success on the Platform Developer I exam comes from a blend of conceptual understanding, memorization of key facts, and lots of hands-on practice. Here are some closing tips to optimize your study:

• Focus on High-Weight Sections First: Since Process Automation & Logic (30%) is the heaviest, ensure you are very comfortable with Apex basics, triggers, and when to use code vs clicks. Next, User Interface (25%) and Developer Fundamentals (23%) are nearly equal – don’t neglect Visualforce/LWC or data model/multi-tenant concepts. Testing & Deployment (22%) is slightly lower, but often easier to score points in with straight memorization (e.g. test coverage rules, sandbox types), so cover those thoroughly as well. Allocate study time roughly in proportion to these weights, but also according to your personal strengths/weaknesses. 

• Leverage Trailhead and Documentation: Salesforce provides official modules and the exam guide (objectives) – use them as a checklist. If you find a topic challenging (say, LWC events or Apex testing), search for specific Trailhead projects or official blog posts on that topic. The Salesforce Developer documentation is also excellent for deep-dives (e.g. the Apex Developer Guide’s chapter on Governor Limits, or Visualforce Developer Guide for VF components).

• Practice in a Developer Org: Reading and memorizing can only take you so far – make sure to implement mini-examples for each key area in an actual org. Create triggers, run tests, build a Visualforce page, and spin up an LWC. This practical experience will make the exam scenarios much easier to parse because you’ve done it, not just read it.

• Use Flashcards and Spaced Repetition: The lists of terms and limits in this guide are ideal for flashcards. For example, put “Max SOQL queries per transaction” on one side and “100 (sync), 200 (async)” on the back. Use a spaced repetition system (like Anki) to drill these facts daily. By exam day, you should instantly recall governor limit numbers, what features are declarative vs code, and the key definitions.

• Join the Community and Discussion: If you get stuck on a concept, chances are someone on the Trailblazer Community or forums (StackExchange, Reddit’s r/salesforce) has asked about it. Sometimes hearing an explanation from a fellow learner or an MVP can make things click. Plus, community threads often highlight which topics recent exam-takers found tricky (e.g., several people emphasize not to ignore Visualforce and roll-up summaries). Just be careful to use community content as a supplement to official info (to avoid any outdated advice).

• Take Practice Exams (but use them wisely): If you have access to practice exams (like those from Focus on Force or others), use them to gauge your readiness after you’ve studied. They can identify weak areas to revisit. However, don’t just memorize practice Q&As – ensure you understand the reasoning behind each answer. The real exam questions will differ, but the underlying concepts will be the same.

• Time Management in the Exam: You’ll have roughly 105 minutes for 60 questions, which is plenty if you know your stuff. However, some scenario questions can be long. Practice reading questions carefully and identifying keywords (e.g. “given a scenario… use declarative vs programmatic” hints at the decision of Flow vs Apex). If a question stumps you, remember elimination techniques: rule out obviously wrong answers (e.g., if a limit is clearly exceeded, any answer suggesting that code works is wrong). Mark tough questions for review and move on – sometimes a later question can jog your memory for a previous one.

By following this guide and approaching your preparation methodically, you will build both the knowledge and the confidence needed to master the Salesforce Platform Developer I exam. Good luck on your certification journey – with diligent study and hands-on practice, you’ll be well on your way to achieving the Platform Developer I credential and advancing your Salesforce development expertise!

Sources: The content above was informed by Salesforce’s official exam guide and documentation, including the Salesforce Certified Platform Developer I Exam Guide, Salesforce Trailhead modules and developer guides, as well as community insights and best practices shared by experienced developers. All effort has been made to ensure accuracy and relevancy as of 2025. Use the cited references for deeper reading on specific topics as needed. Good luck with your studies and exam!