Building integrations that work in production requires more than just connecting two APIs. Here are the patterns that separate reliable integrations from fragile ones.
Idempotency First
Every integration should be idempotent by design. If a message is processed twice, the outcome should be the same as processing it once. This single principle prevents the majority of integration bugs.
Circuit Breaker Pattern
External APIs fail. Implement circuit breakers that detect failures and temporarily stop requests to prevent cascading failures. After a cooldown period, test with a single request before resuming full traffic.
Event-Driven Architecture
Point-to-point integrations create tight coupling. Adopt event-driven patterns where systems publish events and consumers subscribe to what they need. This allows you to add new integrations without modifying existing ones.
Data Transformation Layer
Never assume data formats will remain consistent. Build a transformation layer that normalizes data between systems. This layer absorbs changes in external APIs without affecting your core logic.
Monitoring and Alerting
Every integration needs three types of monitoring: health checks (is it running?), throughput metrics (is it keeping up?), and data quality checks (is the output correct?). Alert on anomalies, not just failures.
Graceful Degradation
Design integrations to degrade gracefully when dependencies are unavailable. Queue operations for retry, provide cached data when fresh data is unavailable, and always communicate system status to users.