What is event sourcing and can you give me some examples?

What is event sourcing and can you give me some examples?

Event sourcing is a software architectural pattern where state changes are stored as a sequence of events. Instead of storing just the current state, you store all the events that lead to that state. For example, in an e-commerce application, instead of just storing the current inventory level, you would store events like 'Item Added to Inventory' or 'Item Sold'.

Can you explain how event sourcing differs from traditional CRUD operations?

Sure! In traditional CRUD (Create, Read, Update, Delete) operations, you typically update the current state directly. In event sourcing, you never overwrite the past; instead, you append new events to a log. This allows you to reconstruct the state at any point in time by replaying the events.

What are some advantages of using event sourcing?

Some advantages include better audit trails, the ability to easily implement complex business logic, and improved scalability. It also allows for easier debugging and the ability to recreate past states.

Are there any downsides to using event sourcing?

Yes, there are some downsides, such as increased complexity in managing event storage and the need for careful design to avoid issues like event schema evolution. It can also lead to larger storage requirements.