event-driven-architect

You can design event-driven microservices using Kafka topics for asynchronous communication, structuring publish/subscribe pipelines for real-time processing and eventual consistency. The architecture separates command and query paths while coordinating distributed transactions through saga workflows.

The saga pattern coordinates distributed transactions by tracking multi-step workflows and executing compensating actions upon failure. You need it when a business process spans multiple microservices and requires eventual consistency without distributed locks.

CQRS with event sourcing rebuilds system state by persisting domain changes as an immutable event log and replaying them. It separates command paths that issue events from query models that project read states, improving scalability and performance.

Asynchronous messaging handlers process duplicate events because message brokers guarantee at-least-once delivery. You must implement idempotent handlers using correlation IDs to deduplicate messages and ensure the same event does not mutate state twice.

Handle event schema versioning by applying backward-compatible evolution rules, and route unprocessable messages to dead-letter queues. This isolates failures in asynchronous pipelines while you monitor event lag and throughput to maintain production system stability.