Meta Full Stack Engineer Interview Questions (2026)

1. 1Recruiter screen30 minEasy

   Process overview, level calibration, and prep guidance — Meta recruiters actively coach on round formats.

2. 2Technical screen45 minHard

   Two DSA problems in 45 minutes on a plain shared editor with no autocomplete or execution.

3. 3Coding round ('Ninja')45 minHard

   Two more problems at loop difficulty; clean near-compilable code and verbalized complexity analysis expected.

4. 4System design ('Pirate')45 minHard

   Design a Meta-scale product system (feed, Stories, chat) with emphasis on read-heavy fan-out, caching, and data modeling.

5. 5Behavioral ('Jedi')45 minMedium

   Deep past-experience discussion on conflict, growth, and impact aligned to Meta values; graded as a real signal round.

1. Q1

   You're building a creator insights API. How would you design webhook delivery for external developers?

   IntermediateFull Loop — Product ArchitectureAPI Design

   How to answer: Sign payloads, retry with backoff, include event IDs, expose delivery logs, and make event payloads replayable. Validate with metrics and scale, product impact, and privacy-aware design.

2. Q2

   You're building a privacy settings API. What should a consistent API error schema include?

   IntermediateFull Loop — API/System DesignAPI Design

   How to answer: Include stable error type, message, affected field, request ID, retryability, and links to docs when helpful.

3. Q3

   You're building a notification preferences API. Which status codes would you use for validation, auth, conflicts, and rate limits?

   IntermediateTechnical Screen — Integration ReasoningAPI Design

   How to answer: Use 400/422 for validation, 401 unauthenticated, 403 unauthorized, 409 conflict, and 429 rate limit with retry metadata.

4. Q4

   You're building a Graph API-style app integration. How would you communicate rate limits to API clients?

   IntermediateFull Loop — Product ArchitectureAPI Design

   How to answer: Return limit headers, reset windows, 429 bodies, retry-after hints, and separate quotas by client, token, and endpoint risk.

5. Q5

   You're building a messaging API. How would an API handle a long-running export request?

   IntermediateFull Loop — API/System DesignAPI Design

   How to answer: Return 202 with an operation ID, expose status and result endpoints, emit webhooks, and make cancellation explicit.

6. Q6

   You're building a creator insights API. How would you define partial updates safely?

   SeniorTechnical Screen — Integration ReasoningAPI Design

   How to answer: Choose JSON Merge Patch or explicit fields, distinguish null from missing, validate transitions, and document idempotency.

7. Q7

   You're building a privacy settings API. How would you design a bulk create endpoint?

   SeniorFull Loop — Product ArchitectureAPI Design

   How to answer: Accept bounded batches, return per-item results, support idempotency, handle partial failures, and document ordering guarantees.

8. Q8

   You're building a notification preferences API. How would you keep API documentation accurate?

   SeniorFull Loop — API/System DesignAPI Design

   How to answer: Generate docs and SDKs from versioned OpenAPI specs, validate examples in CI, and require schema review for changes. Validate with metrics and scale, product impact, and privacy-aware design.

9. Q9

   You're building a Graph API-style app integration. What changes are safe for existing API clients?

   SeniorTechnical Screen — Integration ReasoningAPI Design

   How to answer: Adding optional response fields is usually safe; changing types, meanings, required fields, or error behavior is breaking.

10. Q10

    You're building a messaging API. What should live in an API gateway versus a service?

    SeniorFull Loop — Product ArchitectureAPI Design

    How to answer: Put cross-cutting concerns like routing, auth checks, rate limits, and request IDs at the gateway; keep business rules in services.

11. Q11

    You're building a creator insights API. How would you model permissions for API clients?

    SeniorFull Loop — API/System DesignAPI Design

    How to answer: Use least-privilege scopes, tenant boundaries, explicit resource checks, and separate user-delegated tokens from machine credentials.

12. Q12

    You're building a privacy settings API. How do you make every API request tenant-safe?

    SeniorTechnical Screen — Integration ReasoningAPI Design

    How to answer: Derive tenant from trusted auth context, never request body alone, enforce scoping in queries, and test cross-tenant denial. Keep the design simple enough to operate and debug.

13. Q13

    You're building a notification preferences API. How should an API validate request payloads?

    SeniorFull Loop — Product ArchitectureAPI Design

    How to answer: Validate schema, types, ranges, unknown fields, and domain invariants; return field-level errors with stable codes.

14. Q14

    You're building a Graph API-style app integration. How would you design APIs for unreliable mobile networks?

    SeniorFull Loop — API/System DesignAPI Design

    How to answer: Minimize round trips, support partial responses, compression, retries, idempotency, and offline-safe sync where possible.

15. Q15

    You're building a messaging API. What makes an API SDK pleasant to use?

    SeniorTechnical Screen — Integration ReasoningAPI Design

    How to answer: Typed models, clear errors, retries for safe operations, pagination helpers, examples, and escape hatches for advanced users. Validate with metrics and scale, product impact, and privacy-aware design.

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