- Design normalized schemas
- Add indexes & analyze queries
- Implement transactions
- Test ACID properties
- Dirty reads
- Non-repeatable reads
- Phantom reads
- READ COMMITTED
- REPEATABLE READ
- SERIALIZABLE
- Read replicas
- Write bottleneck simulation
- Vertical vs horizontal scaling (trial)
- Hash-based sharding
- Range-based sharding
- Shard routing logic
- Hash ring implementation
- Node addition/removal
- Minimal rebalancing
- In-memory cache - Redis
- Cache-aside pattern
- Cache hit/miss tracking
- Cache warm-up
- TTL handling
- Cache invalidation
- Write-through / write-back
- App-level cache
- DB query cache
- CDN-style simulation
- Producer–consumer
- Retry mechanism
- Dead-letter queue
- Producer & consumer
- Partitioning
- Consumer groups
- Offset management
- WebSocket pub-sub
- Live notification system
- Round-robin
- Least connections
- Health checks
- Open / closed / half-open states
- Failure thresholds
- Fallback logic
- Data replication
- Backup & restore
- Failover simulation
- Leader election algorithm
- Heartbeats
- Leader failure handling
- File upload/download
- Pre-signed URLs
- Metadata storage
- Implement from scratch
- False positive testing
- Cache-penetration prevention
- API + IP Rate limiter using redis
- Make Scaling Notification ( PUB SUB IGuess)
- Design and implement tinder feed
- Design and implement twitter trends
- Design and implement url shortner
- Design and implement Recommendation system
- Design and implement a web crawler
- Design and implement a fraud detection system