Client–Server Architecture
Section Descriptions
1. Core Model
| File | Topics |
|---|---|
| Responsibilities & Communication | Client/server responsibilities, communication models, HTTP/1.1 vs HTTP/2 vs HTTP/3, TCP vs QUIC, connection reuse |
| API Architectures Overview | REST, GraphQL, gRPC, WebSocket, SSE — quick comparison for architecture decisions |
2. Edge Layer
| File | Topics |
|---|---|
| CDN & Load Balancer | CDN caching, geo distribution, L4/L7 LB, algorithms, health checks, SSL termination, sticky sessions |
| Reverse Proxy & API Gateway | Reverse proxy, forward proxy, API gateway responsibilities, BFF pattern, API composition, facade, WAF |
3. Traffic Management and Service Mesh
| File | Topics |
|---|---|
| Traffic Management | Path/host routing, rate limiting, throttling, canary releases, blue-green deployment, failover |
| Service Layer & Mesh | Monolith vs microservices, REST/gRPC/async internal comms, service aggregation, Istio vs Linkerd |
4. Connections and Backpressure
| File | Topics |
|---|---|
| Connection Management | HTTP keep-alive, connection pooling, HTTP/2 multiplexing, gRPC keepalive + flow control, WebSocket reconnect + heartbeat |
| Backpressure & Flow Control | REST rate limiting algorithms, gRPC HTTP/2 flow control, WebSocket bounded queues, drop strategies, flow signals |
5. Client Architecture, Scalability, Performance
| File | Topics |
|---|---|
| Client Architecture | Data fetching patterns, state management (server/UI/URL/persistent), batching, caching, debounce/throttle |
| Scalability | Horizontal/vertical scaling, bottlenecks, WebSocket sticky sessions + pub/sub, multi-region geo routing |
| Performance | Latency sources, throughput, compression (gzip/brotli), protobuf vs JSON, sparse fieldsets, SLO targets |
6. Reliability, Security, Observability
| File | Topics |
|---|---|
| Reliability | Retry + backoff + jitter, circuit breaker states, timeout policy, graceful degradation, graceful shutdown |
| Security | JWT, OAuth2, mTLS, TLS config, firewall, rate limiting, input validation, WAF, DDoS, CORS |
| Observability | Structured logging, RED metrics, distributed tracing (OpenTelemetry), edge observability (gateway + LB) |
7. Testing, Risks, Patterns, Decisions
| File | Topics |
|---|---|
| Testing | API testing (REST/GraphQL/gRPC/WebSocket), integration testing, load testing, chaos testing |
| Risks & Anti-Patterns | Distributed complexity, tight coupling, stateful scaling, security surface, 6 key anti-patterns |
| Real-World Decision Factors | CDN+REST, GraphQL+BFF, gRPC internal, WebSocket realtime, multi-layer caching, decision guide |