Domain 1: Developer Fundamentals
- Multi-tenant architecture and why governor limits exist, plus the MVC pattern and the Lightning Component framework.
- Declarative versus programmatic customization: when Flow, formula fields, or roll-up summaries suffice and when Apex is required.
- The data model in code: standard and custom objects, fields, and the __c and __r API suffixes.
- Relationship types (lookup, master-detail, many-to-many) and how they enable SOQL relationship queries and cascade delete.
- External IDs and upsert, and how the schema affects describe calls and dynamic SOQL.
- Importing and exporting data into development environments with the Data Import Wizard and Data Loader.
Domain 2: Process Automation and Logic
- Apex data types and collections: List (ordered), Set (unique), and Map (key to value), plus access modifiers, interfaces, and with-sharing rules.
- SOQL and SOSL: relationship queries, aggregate functions, bind variables, and when to search with SOSL instead of query with SOQL.
- DML statements versus Database methods, partial-success handling, and upsert with an external ID.
- Triggers: context variables (Trigger.new, old, newMap, oldMap, isInsert, isBefore, and more), before versus after, and the one-trigger-per-object handler pattern.
- Bulkification and governor limits: never place SOQL or DML in a loop, and understand the order of execution and recursion control.
- Asynchronous Apex (future, Queueable, Batch, Scheduled) and exception handling with try-catch and custom exceptions.
Domain 3: User Interface
- Visualforce pages and the choice of standard controller, standard list controller, custom controller, or controller extension.
- Visualforce markup, expression syntax, getters and setters, and action methods.
- The Lightning Web Components framework, the bundle contents, and the @api, @track, and @wire decorators with lifecycle hooks.
- Lightning Data Service and base components for reading and writing records without Apex, and calling Apex from LWC.
- LWC event handling and component communication, plus Aura awareness and Aura-versus-LWC selection.
- Preventing UI and data-access vulnerabilities: enforcing CRUD and field-level security, and preventing SOQL injection and XSS.
Domain 4: Testing, Debugging, and Deployment
- Writing test classes and methods with @isTest, creating test data in the test, and using @testSetup.
- Test.startTest and Test.stopTest for fresh governor limits and running queued asynchronous work.
- Assertions and the 75 percent org-wide code coverage required to deploy to production.
- Testing triggers in bulk, controllers, and asynchronous Apex, plus mocking callouts.
- Developer tools: the Developer Console, debug logs and levels, the Salesforce CLI, and Salesforce DX.
- Deployment with change sets, the Metadata API, and packages (managed, unmanaged, unlocked), plus sandbox types and use cases.
Salesforce Certified Platform Developer I exam tips
- Process Automation and Logic is the heaviest area at 30 percent and is the heart of the exam. Be fluent with Apex collections (List, Set, Map), SOQL and SOSL, DML versus Database methods, triggers and their context variables, bulkification, the order of execution, and asynchronous Apex.
- This is a code exam. Expect Apex and SOQL snippets in the questions. Know the governor limits (100 SOQL, 150 DML, 50,000 query rows synchronously) and why putting a query or DML inside a loop breaks a bulk transaction.
- For testing, remember the essentials: test methods see no org data by default, create your own test data, use Test.startTest and Test.stopTest, assert results with a message, and you need 75 percent org-wide coverage to deploy - coverage measures lines executed, not assertions.
- Know your async options and when each fits: future for simple fire-and-forget and callouts, Queueable for chained jobs that take objects, Batch for large data volumes, and Scheduled for time-based runs.
- For User Interface, be able to pick the right Visualforce controller type, know the LWC decorators and Lightning Data Service, and recognize security must-dos like WITH SECURITY_ENFORCED, stripInaccessible, bind variables, and escaping user input.
Study guide FAQ
How many questions are on the exam and what is the passing score?
There are 60 scored multiple-choice and multiple-select questions in 105 minutes, and you need 68 percent to pass. Up to five additional unscored questions may be included. The exam is proctored online or at a test center, and the registration fee is 200 USD.
Do I need to write code to pass?
Yes. Platform Developer I is a programmatic exam. You need to read and reason about Apex, SOQL and SOSL, triggers, and test classes, and understand Visualforce and Lightning Web Components. It is the pro-code counterpart to the declarative Platform App Builder exam.
Is there a prerequisite?
No formal prerequisite. Salesforce recommends one to two years of general development experience and at least six months building on the Lightning Platform. Administrator or App Builder knowledge is helpful background.
What is out of scope for PD1?
Integrations such as callouts and APIs, email services, managed-package publishing, and mobile app development are out of scope for Platform Developer I. The focus is Apex logic, data, the user interface, and testing and deployment on the core platform.
Is CertGrid practice official Salesforce material?
No. CertGrid is an independent practice platform and is not affiliated with or endorsed by Salesforce. These questions are original and written to mirror the current exam objectives so you can rehearse them. Always confirm the current exam guide on Trailhead before your exam.