How do you design a resilient integration architecture for a Salesforce-to-ERP integration handling high transaction volumes?

A resilient high-volume Salesforce-to-ERP integration requires addressing several architectural concerns:

Decoupling: Use Platform Events or a message queue (MuleSoft, AWS SQS) between Salesforce and the ERP. Salesforce publishes events; the ERP consumer processes at its own pace. This prevents Salesforce governor limits from being blocked by slow ERP responses.

Idempotency: Assign a unique transaction ID to every message. The ERP ignores duplicates based on this ID — critical when retries occur.

Error handling: Implement a dead-letter queue for failed messages. Route to a monitoring/alerting system (e.g., Slack, PagerDuty). Store failed records in a Salesforce custom object for manual review and replay.

Batching: Aggregate individual Salesforce record changes into micro-batches before calling the ERP if the ERP has per-call overhead. Use Schedulable Apex or a Queueable chain to bundle records.

Circuit breaker: Detect ERP unavailability using failure thresholds stored in Custom Metadata. Stop sending during ERP downtime; backfill via replay when restored.

Monitoring: Log every integration transaction (request, response, status, timestamp) to a custom object or external logging platform. Set up Salesforce reports/dashboards for integration health metrics.