System Design Interview - What topics do you expect to cover?

07 Aug 2025

Here is probably an exhausitive list of System Design Topics that you can use to prepare for your System Design interviews. Source: LinkedIn.

These are my notes for my own reference. Read some reference documentation for more accurate and up-to-date details on how these are put in action by different software products and companies.

Scaling & Architecture

↬ CDN ↬ Caching ↬ Sharding ↬ Queueing ↬ Replication ↬ Partitioning ↬ API Gateway ↬ Rate Limiting ↬ CAP Theorem ↬ Microservices ↬ Load Balancing ↬ Fault Tolerance ↬ Database Scaling ↬ Service Discovery ↬ Consistency Models ↬ Eventual Consistency ↬ Distributed Transactions ↬ Monolith vs Microservices ↬ Leader Election

Databases & Storage

↬ Leader-Follower Replication ↬ WAL (Write Ahead Log) ↬ Asynchronous Processing ↬ Transaction Isolation ↬ Read/Write Patterns ↬ Consistent Hashing ↬ Redis/Memcached ↬ Backup & Restore ↬ Hot/Cold Storage ↬ Data Partitioning ↬ Object Storage ↬ SQL vs NoSQL ↬ Data Retention ↬ Data Modeling ↬ OLAP vs OLTP ↬ ACID & BASE ↬ Bloom Filters ↬ File Systems ↬ S3 Basics ↬ B+ Trees ↬ Indexing

Communication & APIs

↬ JWT ↬ CORS ↬ OAuth ↬ Throttling ↬ Serialization ↬ API Security ↬ Long Polling ↬ WebSockets ↬ API Gateway ↬ Idempotency ↬ Service Mesh ↬ Retry Patterns ↬ REST vs gRPC ↬ API Versioning ↬ Circuit Breaker ↬ API Rate Limits ↬ Fan-out/Fan-in ↬ Protocol Buffers ↬ Message Queues ↬ Dead Letter Queue

Reliability & Observability

↬ Metrics ↬ Alerting ↬ Failover ↬ Logging ↬ Rollbacks ↬ Monitoring ↬ Heartbeats ↬ Retry Logic ↬ Autoscaling ↬ SLO/SLI/SLA ↬ Load Testing ↬ Error Budgets ↬ Health Checks ↬ Circuit Breaker ↬ Incident Response ↬ Chaos Engineering ↬ Distributed Tracing ↬ Canary Deployments ↬ Graceful Degradation ↬ Blue-Green Deployment