sde-system-design

RESTful API contract with auth, rate limits, pagination, error schema, and versioning

Full High-Level Design — clarify requirements, estimate capacity, design components, model data, define APIs, deep dive bottlenecks, enumerate failure modes

Capacity estimation worksheet — QPS, storage, bandwidth, cache sizing with worked numbers and scale implications

Entity-relationship diagram + schema + index strategy matched to access patterns

REST/GraphQL/gRPC API contracts with versioning, auth, pagination, error formats, and rate limiting. Use when designing a new API or reviewing an existing one for production readiness.

Cache topology, eviction policies (LRU/LFU/TTL), and cache-aside vs write-through vs write-behind patterns. Use when adding caching to a system or debugging cache performance issues.

Back-of-envelope capacity estimation: QPS, storage, bandwidth, cache sizing with worked numbers and scale implications. Use when sizing infrastructure or answering 'how big does this need to be?'

Schema design, normalization levels, indexing strategy matched to access patterns. Use when designing database schemas, choosing between embed vs reference, or optimizing slow queries.

RDBMS vs document vs wide-column vs graph vs time-series — tradeoffs matched to access patterns and team context. Use when choosing a database for a new service or evaluating whether to migrate.

CAP theorem applied to real decisions, consensus (Raft/Paxos), distributed transactions, saga pattern, idempotency. Use when designing systems that span multiple nodes or services.

7-phase High-Level Design framework: clarify requirements, estimate scale, design components, model data, define APIs, deep dive on bottlenecks, and enumerate failure modes. Use for any system design question or production architecture task.

Kafka/SQS/RabbitMQ/Bull topology, ordering guarantees, consumer groups, DLQ patterns. Use when decoupling async work from the request path or building event-driven pipelines.