Visa Flexible Credentials

Payment acknowledgements travelled over TCP socket connections carrying raw byte streams. The connections were unreliable, and the traffic was 40M transactions a day against a 5-second SLA.

Architected a Kafka-driven acknowledgement system to replace the sockets.

Built observability for it directly on the Kafka Admin API, surfacing consumption per partition through Prometheus and Grafana — so a lagging partition is visible before it becomes a breached SLA.

Acknowledgements for 40M transactions a day now run over Kafka rather than raw sockets, inside the 5-second SLA, with per-partition consumption visible while it happens.