Handling Eventual Consistency

Microservices often trade immediate consistency for eventual consistency.

Each service owns its data, and updates usually propagate through events. That means one service may see a change before another does. For a short time, different parts of the system can disagree.

This is normal, but users should not feel like the app is broken.

This chapter covers read-your-writes behavior, handling lag, safe retries, concurrent updates, and when strong consistency is still required.