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.
SDK and Client Library Design
Packaging an API for developer consumption via SDKs and client libraries: ergonomic method surfaces, auth handling, pagination helpers, retry/backoff built in, error mapping, and versioning of generated or hand-written clients. Covers cloud/mobile SDK design, code generation from contracts, and keeping SDKs consistent across languages.
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 Versioning, Deprecation and Backward Compatibility
Evolving an API without breaking existing consumers: versioning strategies (URI, header, media-type), distinguishing breaking from non-breaking changes, deprecation policies and sunset timelines, and coordinating migrations at scale. Covers communicating changes, supporting multiple versions concurrently, and compatibility guarantees across heterogeneous clients.
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.
Data Synchronization and Integration Consistency
Keeping data consistent across integrated systems: batch vs. real-time sync, change data capture, conflict resolution, reconciliation, and eventual consistency across service boundaries. Covers diagnosing and preventing drift, ordering and deduplication in sync pipelines, and the trade-offs between tight and loose coupling for shared data.