Integrating systems without creating a spider web

One owner per fact

For every important fact, such as a customer address or a stock level, decide which system is authoritative and which systems receive copies. Duplicate ownership is the root cause of most reconciliation work.

Design for failure from day one

Networks fail, rate limits trigger, and third-party APIs change. Every integration needs retries with backoff, a dead-letter queue for messages that keep failing, and an alert that reaches a human.

Ids should be stable and idempotent writes should be the default, so a retried request does not create a duplicate order.

Observe the pipes

Log every request with correlation ids, track latency and failure rate per integration, and build one dashboard that shows whether data is flowing. Silent integration failures are discovered by customers, which is the worst way.