State Management with Event Sourcing

Explain the core principles of event sourcing and how it differs from traditional state-oriented persistence.

Design aggregate roots and domain events for a financial scenario from your experience (e.g., FX trade lifecycle).

Implement event replay to reconstruct the current state of an aggregate from its historical event stream.

Implement snapshots for an aggregate to optimize state reconstruction performance for long-lived objects.

Explain common strategies for event schema evolution (e.g., upcasting, lazy migration) and their trade-offs.

Implement an upcaster function in Python to transform an older event version into the current version during state reconstruction.

Analyze the benefits and drawbacks of event sourcing, identifying use cases where it is and is not appropriate.