Pattern of storing all changes to application state as a sequence of events. Like keeping a detailed diary of everything that happened instead of just the current situation.
Banking systems use event sourcing to track every transaction, allowing them to reconstruct account balances at any point in time.
While no cloud provider offers a direct service named Event Sourcing, they provide tools like AWS Lambda, Azure Functions, and Google Cloud Pub/Sub that can be used to implement event-driven architectures.