Event-Driven Commerce Platform

Designed and shipped an event-driven order platform on NestJS and Kafka with exactly-once processing semantics at the consumer boundary, idempotent command handlers, and a replayable event log that serves as the system of record. Read models are derived asynchronously into Postgres and Elasticsearch.

Highlights

• Outbox pattern + transactional producer for zero lost events
• Per-aggregate partitioning preserves ordering without global locks
• Schema registry (Avro) with backward-compatible evolution