Preparing for a Salesforce developer interview in 2026 requires more than just memorizing definitions. Recruiters and hiring managers expect you to demonstrate a deep understanding of Salesforce multitenancy, governor limits, trigger patterns, and advanced asynchronous processing. This guide covers a structured set of questions from beginner concepts to advanced scenarios to ensure you clear your technical assessment.
Beginner Questions (Foundational Concepts)
1. What are Governor Limits in Salesforce, and why are they crucial?
Governor Limits are runtime resource restrictions enforced by the Salesforce multi-tenant architecture. Since code runs on shared hardware, limits prevent any single transaction from monopolizing resources like memory, database, or CPU. In your preparation, make sure you are familiar with the synchronous 100 SOQL query limit, 150 DML statement limit, and 10-second CPU time limit. For more details, explore our comprehensive Governor Limits page.
2. What is the difference between Custom Metadata Types and Custom Settings?
Custom Metadata Types allow you to define configuration settings that can be packaged, deployed via change sets or DevOps pipelines, and queried without consuming governor limits in certain scenarios. Custom Settings data, on the other hand, is treated as record data and cannot be easily migrated across environments without data loading tools.
Intermediate Questions (Logic & Operations)
3. How do you implement a Trigger Handler Framework?
Trigger frameworks are designed to keep trigger files lightweight by separating context management from business logic. A strong trigger architecture prevents nested trigger execution, enforces logic ordering, and supports programmatic bypasses. Check out our Trigger Interview page for detailed trigger guidelines.
4. When should you use Queueable Apex instead of future methods?
Queueable Apex provides several advantages over future methods: it supports complex types (objects, custom classes) rather than just primitives, it returns a job ID that can be monitored, and it allows job chaining to sequentialize async steps. Always suggest Queueable for robust asynchronous architecture.
Advanced Questions (Architectural Scaling)
5. What are the best practices for bulkifying SOQL and DML operations?
Bulkification is the process of writing code that handles multiple records gracefully, rather than just single transactions. You must never place SOQL queries or DML statements inside loops. Instead, collect IDs in a Set, execute a single query, map the results, and perform DML on a unified list.
| Pattern | Weak Code (System.LimitException Risk) | Strong Scale-Safe Code |
|---|---|---|
| SOQL inside Loop | for(Id acId : ids) { Account a = [SELECT Id FROM Account WHERE Id = :acId]; } | List<Account> accounts = [SELECT Id, Name FROM Account WHERE Id IN :ids]; |
| DML inside Loop | for(Account a : list) { update a; } | List<Account> toUpdate = new List<Account>(); ... update toUpdate; |
SOQL inside Loop
for(Id acId : ids) { Account a = [SELECT Id FROM Account WHERE Id = :acId]; }
List<Account> accounts = [SELECT Id, Name FROM Account WHERE Id IN :ids];
DML inside Loop
for(Account a : list) { update a; }
List<Account> toUpdate = new List<Account>(); ... update toUpdate;
6. How do you prevent CPU time limit exceptions in complex transactions?
CPU timeout exceptions occur when transactions spend more than 10 seconds executing code in the thread. To optimize, use Maps for fast record lookup, avoid nested loop iterations, reduce formula fields referencing parents in queries, and offload CPU-heavy processing to async threads (Queueable or Batch Apex).
Scenario-Based Questions (Recruiter-Grade Cases)
Scenario 1: A batch process of 1 million records is failing due to heap limits. How do you resolve this?
To optimize heap size limits, process records in smaller scopes (e.g., reduce Batch size from 200 to 50), query only the fields required for execution, use SOQL for loops to process records in batches of 200, and explicitly nullify heavy variables after they are processed.
Scenario 2: You need to make a callout to an external API whenever a record is created, but the trigger context restricts callouts.
You cannot perform web callouts directly from a trigger thread as it would block the transaction. Instead, invoke a Queueable job from the trigger. This moves the integration callout into an asynchronous execution path and allows the user's save transaction to complete instantly.
FAQ Section (Salesforce Apex Interview FAQs)
- Can we call a batch class from another batch class? -> Yes, you can start a batch job from the finish method of another batch job, which is a standard pattern for chaining sequential processes.
- What is the difference between Database.insert and simple insert? -> Simple insert enforces all-or-nothing rollback on errors. Database.insert with allOrNone = false allows partial success, letting valid records save while returning errors for failing ones.
- How do you test callouts in Apex? -> You must implement the HttpCalloutMock interface to simulate responses without making actual HTTP network requests, as live callouts are blocked in test classes.
Ready for your Interview?
To practice explaining these concepts out loud and receive detailed AI feedback, prepare with our Mock Interview page. You can choose Strict or Mentor recruiters to test your verbal delivery and concept coverage. Or check our main Apex Interview page for specific question catalogs.