Projections in Event Sourcing: Build ANY model you want!

Projections in Event Sourcing are a way to derive current state from an event stream. This can be done asynchronously as events are persisted to an event stream which can update a projection. You don’t need to replay all the events in an event stream to get to current state for a UI every time you need to display data. This could be very inefficient if you have a lot of events in a stream. Rather, create a projection that represents current state and keep it updated as events occur.

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0:00 Intro
1:23 Projections Explained
4:01 Publish/Subscribe
6:42 Code Implementation Example

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