1. 1. What's the difference between List, Set, and Map in Apex?

   List: ordered collection with duplicates; Set: unique values; Map: key-value pairs for lookups

2. 2. Explain the difference between == and .equals() in Apex.

   == compares references for objects, values for primitives; .equals() compares actual content/values

3. 3. What are governor limits and why do they exist?

   Platform limits to ensure fair resource usage: SOQL queries (100), DML statements (150), CPU timeout (10s)

4. 4. How do you handle exceptions in Apex? Give examples of built-in exception types.

   try-catch-finally blocks; DmlException, QueryException, NullPointerException, LimitException

5. 5. What's the difference between static and instance methods?

   Static: belongs to class, no object needed; Instance: requires object instantiation, can access instance variables

6. 6. Explain Apex sharing and security. What's runAs() used for?

   System vs user mode execution; runAs() tests code execution as specific user for security testing

7. 7. What are future methods and when would you use them?

   Asynchronous execution with @future annotation; used for callouts, long-running processes, mixed DML operations

8. 8. How do you implement batch processing in Apex?

   Database.Batchable interface with start(), execute(), finish() methods; processes large data sets in chunks

9. 9. What's the difference between Database.insert() and insert statement?

   Database.insert() allows partial success with allOrNone parameter; insert statement fails entire transaction on error

10. 10. Explain the use of with sharing, without sharing, and inherited sharing keywords.

    Controls record-level security enforcement: with (enforces), without (ignores), inherited (uses caller's context)

11. 11. What's the lifecycle of a Lightning Web Component?

    constructor() → connectedCallback() → renderedCallback() → disconnectedCallback() → errorCallback()

12. 12. How do you pass data between parent and child components?

    Parent to child: @api properties; Child to parent: custom events with dispatchEvent()

13. 13. What's the difference between @track, @api, and @wire decorators?

    @api: public properties; @track: deprecated (use reactive properties); @wire: connects to Salesforce data

14. 14. How do you handle events in Lightning Web Components?

    Event handlers with addEventListener(), template onclick handlers, custom events with CustomEvent

15. 15. How do you call Apex methods from LWC?

    @wire for reactive data, imperative calls with import and .then()/.catch(), @AuraEnabled methods

16. 16. What's the difference between SOQL and SOSL?

    SOQL: queries single object with relationships; SOSL: searches across multiple objects and fields with text search

17. 17. How do you optimize SOQL queries for better performance?

    Use selective filters, indexed fields, LIMIT clause, avoid wildcards in LIKE, minimize subqueries

18. 18. Explain relationship queries in SOQL. Give examples of parent-to-child and child-to-parent.

    Child-to-parent: Account.Name; Parent-to-child: (SELECT Name FROM Contacts) - uses relationship names

19. 19. What happens when you exceed SOQL query limits?

    LimitException thrown; use efficient queries, bulkify code, consider async processing for large datasets

20. 20. How do you handle dynamic SOQL queries safely?

    Use Database.query() with bind variables, String.escapeSingleQuotes() to prevent SOQL injection

21. 21. What are the different trigger contexts and when do they fire?

    before insert/update/delete (validation), after insert/update/delete/undelete (related records), before/after delete

22. 22. How do you write bulkified triggers?

    Process collections, avoid SOQL/DML inside loops, use Maps for lookups, delegate logic to handler classes

23. 23. What's the order of execution for automation tools?

    Workflow rules → before triggers → validation → after triggers → assignment rules → auto-response → workflow field updates

24. 24. When would you use Process Builder vs Flow vs Apex triggers?

    Flow: complex logic, user interaction; Process Builder: simple automation (deprecated); Triggers: bulk processing, complex validation

25. 25. How do you prevent recursive triggers?

    Static variables to track execution, trigger handler patterns, check Trigger.isExecuting context

26. 26. What's the difference between REST and SOAP APIs in Salesforce?

    REST: lightweight, JSON, stateless; SOAP: XML, stateful, more secure, supports transactions

27. 27. How do you handle callout limits and timeouts?

    100 callouts per transaction, 120s total timeout; use future/queueable for async, implement retry logic

28. 28. Explain different authentication methods for Salesforce APIs.

    OAuth 2.0, JWT bearer token, username-password, SAML assertions - OAuth preferred for security

29. 29. How do you implement platform events for real-time integration?

    Publish with EventBus.publish(), subscribe with trigger or Lightning components, decouple systems

30. 30. What are the security considerations when exposing Salesforce data via APIs?

    Field-level security, sharing rules, IP restrictions, API versioning, rate limiting, audit trails

The "Why vs What" Approach

Salesforce interviews focus heavily on architectural decisions. Don't just explain what you'd do—explain why it's the right approach:

• Declarative first: "I'd start with Process Builder because... but if we need bulk processing, then triggers because..."
• Governor limits: "This approach uses fewer SOQL queries because..."
• Maintainability: "Future developers will understand this pattern because..."
• Scalability: "When we have 10,000 records, this solution will..."

Common Salesforce Interview Red Flags

Role-Specific Focus Areas