FAANG Interview Scenarios

Real-world problems that actually appear in Microsoft, Google, Meta, Amazon, and Apple interviews. Each scenario is designed to test senior/staff engineering judgment.

How to Use These Scenarios

1. Read the problem - Don't jump to the solution
2. Take 5 minutes to outline your approach
3. Compare with the provided solution
4. Practice explaining your approach out loud (interviews are verbal!)

Scenario Categories

🔄 Migrations & Transitions

Scenario	Difficulty	Key Skills
Shared Database Split	⭐⭐⭐	Strangler fig, dual writes
Monolith to Microservices	⭐⭐⭐⭐	Service boundaries, incremental migration
Cloud Provider Migration	⭐⭐⭐⭐⭐	Multi-cloud, data sync, DNS

💥 Incident Response & Debugging

Scenario	Difficulty	Key Skills
Deployment Cascade Failure	⭐⭐⭐⭐	Circuit breakers, recovery
Memory Leak Hunt	⭐⭐⭐	Profiling, heap analysis
The Query That Sometimes Takes Forever	⭐⭐⭐⭐	Query plans, statistics

⚡ Performance & Scale

Scenario	Difficulty	Key Skills
Backpressure Handling	⭐⭐⭐⭐	Flow control, load shedding

🔒 Security & Compliance

Scenario	Difficulty	Key Skills
PII Leaked in Logs	⭐⭐⭐⭐	Data scrubbing, compliance
Rate Limiting Bypass Attack	⭐⭐⭐⭐	Distributed rate limiting

🌍 Distributed Systems

Scenario	Difficulty	Key Skills
Event Ordering Problem	⭐⭐⭐⭐	Vector clocks, causal consistency
Cross-Region Consistency	⭐⭐⭐⭐⭐	CRDTs, conflict resolution

🐛 Edge Cases & Bugs

Scenario	Difficulty	Key Skills
Double-Click Double-Charge	⭐⭐⭐	Idempotency keys
Unicode Broke Our System	⭐⭐⭐	Encoding, normalization

📊 Data & Analytics

Scenario	Difficulty	Key Skills
A/B Test Gave Wrong Answer	⭐⭐⭐⭐	Statistics, sample size
Search Ranking Disaster	⭐⭐⭐⭐	ML rollout, monitoring

🔧 Operations & DevOps

Scenario	Difficulty	Key Skills
DNS Change Gone Wrong	⭐⭐⭐	TTL, propagation
All Users Logged Out	⭐⭐⭐⭐	Session management, recovery
Feature Flag Explosion	⭐⭐⭐	Flag lifecycle, cleanup
Partial Batch Job Failure	⭐⭐⭐⭐	Checkpointing, idempotency

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Interview Tips

What Interviewers Look For

Signal	How to Demonstrate
Problem decomposition	Break big problem into phases
Risk awareness	Discuss what could go wrong
Trade-off analysis	Present options with pros/cons
Production mindset	Consider monitoring, rollback
Communication	Think out loud, ask questions

Common Mistakes

1. ❌ Jumping to solution without understanding problem
2. ❌ Over-engineering (adding unnecessary complexity)
3. ❌ Forgetting rollback/recovery plan
4. ❌ Ignoring monitoring and observability
5. ❌ Not discussing trade-offs

Time Management (45-minute interview)

Phase	Time	What to Do
Clarify	5 min	Ask questions, confirm scope
Outline	5 min	High-level approach
Detail	25 min	Deep dive into solution
Trade-offs	5 min	Alternatives, pros/cons
Q&A	5 min	Interviewer questions

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Start with any scenario - they're all independent!