Migrating from Synchronous REST to Kafka-based Messaging

Placeholder post — replace this with the full write-up.

Why we moved away from REST

Synchronous REST calls between services create tight coupling: if the downstream service is slow or down, the upstream call fails or blocks. For a critical cross-service workflow, this became a scalability and reliability bottleneck.

The migration approach

• Identified the workflow boundaries and message contracts.
• Introduced Kafka topics with clear ownership per service.
• Ran REST and Kafka paths in parallel during rollout to validate parity.
• Cut over gradually with feature flags and monitored lag and error rates.

Results

Improved throughput, fault tolerance, and system decoupling. Failures in one service no longer cascade — messages wait in the topic until consumers recover.

What I'd do differently

More on this soon — this is a placeholder to be expanded.