System Integration

System integration connects applications, data, services, and devices so they can deliver an outcome together. Start with the business flow, data ownership, participating systems, and failure behavior. Then select synchronous APIs, asynchronous messages, events, batch transfer, or orchestration according to the interaction need. An integration boundary needs a contract, authentication, authorization, compatibility rules, observability, ownership, and recovery behavior. Direct APIs fit an immediate request and response. Messaging decouples time and can buffer work. Events announce facts for independent consumers. Batch transfer fits large or scheduled exchange.