API & Integration Architecture
Contracts between systems, and the compatibility discipline that keeps them working.
20 topics in this area.
Each topic is the unit content is filed against. Topics with nothing in them yet are shown too — they are the honest edge of the curriculum rather than a gap being hidden.
API & Integration
General material on integrating systems through contracts.
REST Design
Resources, uniform methods, status codes and statelessness.
GraphQL
Client-specified queries, N+1 resolution and query-cost control.
gRPC APIs
Contract-first RPC, generated clients and protobuf compatibility rules.
Webhooks
Push callbacks, signature verification, ordering and at-least-once delivery.
API Versioning
URL, header and account-pinned versioning, and who carries the burden.
Backward Compatibility
Which changes are safe, and how to make breakage a build failure.
Contract Testing
Verifying what consumers actually rely on, without a shared environment.
API Documentation
OpenAPI as a machine-checked contract rather than as prose.
Rate Limiting
Algorithms, shared counters, and signalling rejection properly.
Idempotency Keys
Client-generated keys stored atomically with the operation they guard.
Pagination & Filtering
Offset versus cursor, stable ordering and unbounded result sets.
API Error Handling
Error shapes, retryability signals and machine-readable causes.
Event-Driven Integration
Publishing facts rather than commands, and versioning event schemas.
Message Formats
JSON, Protobuf, Avro — schema evolution and payload economics.
Schema Registry
Enforcing compatibility on events the way CI enforces it on code.
Integration Patterns
Routers, translators, splitters, aggregators and dead letter channels.
Legacy Integration
Reaching systems that cannot change, without importing their model.
Partner & B2B Integration
External contracts, onboarding, sandboxes and long deprecation windows.
APIs as Products
Ownership, lifecycle, deprecation policy and developer experience.