An ERP system must be notified in near real time when an order is activated in Salesforce, and the ERP is sometimes unavailable. What integration approach would you propose?

I would decouple the systems with an event-driven approach: publish a platform event or use Change Data Capture when the order is activated, and have middleware or the ERP subscribe. Event retention lets subscribers replay missed events after an outage, within the retention window.

If a direct callout is required, I would make it asynchronous with retry logic and log failures to a custom object for monitoring and reprocessing. Either way, the ERP should process messages idempotently using a unique key.

Interviewers want the candidate to address reliability, not just connectivity. Strong answers mention replay, idempotency, monitoring and error handling. A pitfall is proposing synchronous callouts with no handling for downtime.