Scratches | David Hull

Microservices need a way to synchronize their data and roll back state, where possible.
AWS Step functions allow implementation of a Saga Execution Coordinator
- Builds a centralized store of critical reference data
- curated by master data management tools and procedures
Using Lambda and scheduled Amazon CloudWatch events you can build a simple cleanup and deduplication mechanism

Event Sourcing is useful where state changes affect multiple microservices
- Persists every application change as an event record
- Doesn't record application state
- Data is stored as a stream of events
State can be determined and reconstructed at any point in time
Produces a persistent audit trail
Assists in debugging