Python Data and Distributed Systems — Senior¶

Distributed correctness comes from explicit invariants, not reliable-looking code.

• Define consistency needs per workflow.
• Use an outbox or durable workflow when a database write must trigger a message.
• Handle duplicate, delayed, and reordered events.
• Plan migrations for old and new application versions running together.
• Observe connection saturation, slow queries, replication lag, and retry volume.

Design failure paths before adding a new dependency or asynchronous boundary.