Cianplan

Level 3: Distributed systems · L3.4 Sagas, outbox, CQRS & event sourcing

Event sourcing and workflow engines

Explain event sourcing and when a workflow engine (Temporal, Step Functions) helps.

12 min · Pro

What you take away

  • Event sourcing stores state as an append-only log of events; current state is a fold over that log, not a row you overwrote.

And 3 more inside the class, in Pro.

How the class is laid out

  1. The problem
  2. The simple version
  3. What event sourcing costs
  4. Workflow engines
  5. Sagas
  6. Outbox
  7. CQRS
  8. Event sourcing
  9. Workflow engines
  10. Check your understanding