Integration Design
An integration is how two systems exchange data. This is where the most expensive bugs are born: lost messages, duplicated orders, hung synchronous calls. An analyst designs the exchange so it survives failures and load growth.
The traps, named up front: choosing the technology before the business need, confusing sync with async, orchestration with choreography, and treating a broker as an accelerator for synchronous calls. And delivery guarantees and idempotency are almost always forgotten. The full map is in the layers below.
Topic map
- Kinds of integration — APIs, brokers and queues,
ESB, file exchange, and a directDB-connect. - Integration topologies — point-to-point vs star/bus and why the number of links explodes.
- Sync, async, and orchestration — the difference between interactions, orchestration vs choreography, and the order of working out an integration.
- Message brokers — why a broker is needed, delivery guarantees, dead-letter, and error handling.
Common traps
| Mistake | Consequence |
|---|---|
| Choosing the technology before the business need and data | The project is reworked; the integration solves nothing |
| Swapping sync and async | A wrong model of system behavior and coupling |
| Confusing orchestration (a center) and choreography (events) | Responsibility is distributed wrongly |
| Treating a broker as an accelerator for synchronous calls | Its essence — decoupling and async — is missed |
| Forgetting delivery guarantees and idempotency | Messages are lost or applied twice |
| Claiming point-to-point scales for free | The number of links explodes as systems grow |
Interview relevance
The topic is asked to check whether you can design a reliable exchange, not just name "REST and Kafka". A candidate who starts from the business need and volumes, and builds in delivery guarantees from the start, sounds like a mature integration analyst.
Typical checks:
- The kinds of integration and when each fits (file vs API vs broker).
- The sync/async and orchestration/choreography difference.
- Why a broker: decoupling, guaranteed delivery, load smoothing.
- The order of working out an integration design — from the business need to error handling.
Common wrong answer: "first pick the technology, say gRPC, and write the code". In fact design starts from the business need, the participants, the exchange regulation, and quantitative metrics; the technology comes last.