Eliminating the dual-write problem in distributed microservices using PostgreSQL and Apache Kafka: implementing the Transactional Outbox Pattern with Debezium CDC, partition key hashing, idempotent consumer processing, and dead-letter retry topologies.
Safely evolving relational database schemas without maintenance windows or lock contention: the 5-phase Expand and Contract lifecycle, lock-free column additions, asynchronous batch backfills, and blue-green API deployment backward compatibility.
