A reliable integration must be treated as an operational product: it has an owner, a data contract, monitoring, failure criteria and an evolution strategy.
APIs and integration platforms help decouple systems, but they do not replace architecture decisions. The right granularity, event handling, idempotency and observability remain decisive.
The goal is to let the ecosystem change without turning every enhancement into a risk-containment project. Good architecture makes dependencies explicit and lowers the cost of understanding what happens end to end.
A question for the next decision
What evidence must be available for your organisation to move forward with confidence — and which risk must be reduced first?