Backend System Design
Backend system design interviews evaluate your ability to design systems that are scalable, reliable, and maintainable — and to explain trade-offs clearly under time pressure. Use this hub like a curriculum: framework first, then core concepts, then full design questions.
| Trade-off | Option A | Option B |
|---|---|---|
| SQL vs NoSQL | ACID compliance, complex queries | Horizontal scale, flexible schema |
| Consistency vs Availability | Financial data, inventory | Social feeds, analytics |
| Push vs Pull | Real-time requirements | High fan-out scenarios |
| Cache vs Database | Read-heavy, latency-critical | Write-heavy, consistency-critical |
| Sync vs Async | Simple flows, immediate feedback | Decoupling, reliability |