APIs, Networking & Integration Topics
API design, management, and integration patterns including REST, GraphQL, and other protocols. Covers API contract design, versioning strategies, error handling, idempotency, deprecation planning, and SDK/integration frameworks. Includes system-to-system integration, webhook patterns, and integration platform considerations. Excludes network infrastructure and network-layer protocols (see Network Architecture under Cloud & Infrastructure or a dedicated networking category if needed).
Enterprise Application Integration
Connecting large, heterogeneous enterprise systems into a coherent whole: interoperability across legacy and modern platforms, integration architecture for digital transformation, standards-based interfaces, and system-of-record coordination. Covers integration platforms/middleware, canonical data models, and the interoperability and governance concerns of complex multi-system landscapes.
gRPC and Service-to-Service Communication
Efficient inter-service communication using RPC-style contracts: gRPC, Protocol Buffers, streaming modes, and binary serialization trade-offs versus JSON/REST. Covers synchronous request/response between microservices, service discovery, deadlines/timeouts, and choosing a transport for internal versus public-facing traffic.
API and Integration Troubleshooting
Diagnosing failures across API and integration boundaries: reading status codes and error payloads, tracing requests across services, latency and timeout investigation, TLS/CORS/auth failures, and pinpointing whether a fault is client, network, gateway, or provider. Covers logging/observability for integrations and systematic debugging of intermittent sync and connectivity issues.
HTTP Protocol and Web Fundamentals
Application-layer HTTP semantics that underpin API behavior: methods, status codes, request/response headers, content negotiation, caching (ETags, Cache-Control), cookies, connection reuse, and HTTP/1.1 vs. HTTP/2 vs. HTTP/3 differences. Includes TLS/HTTPS at the request level and how proxies and load balancers affect requests. Foundational knowledge assumed before deeper API topics.
API Gateways and API Management
The management layer in front of APIs: gateways for routing, authentication, rate limiting, request/response transformation, and observability. Covers API management concerns such as developer portals, key provisioning, plan/tier enforcement, analytics, and centralized policy. The operational and productization surface of an API program.
Rate Limiting, Throttling and Quota Management
Protecting API capacity and enforcing fair use: rate-limiting algorithms (token bucket, leaky bucket, fixed/sliding window), per-client quotas, throttling responses (429 semantics, Retry-After), and tiered plan enforcement. Covers where to enforce limits (gateway vs. service), distributed counters, and graceful degradation under load.
Real-Time APIs with WebSockets and SSE
Building bidirectional and streaming interfaces: WebSockets, Server-Sent Events, and long-polling for live data. Covers connection lifecycle, scaling stateful connections, presence/heartbeats, backpressure, and choosing among real-time transports. Includes mobile and browser client considerations for persistent connections.
Webhooks and Event-Driven Integration
Push-based integration where a provider notifies consumers of events: webhook delivery, signing/verification, retry and dead-letter handling, ordering and deduplication, and idempotent receivers. Covers designing outbound webhook systems, replay/backfill, and comparing webhooks to polling for third-party integration.