Event Sourcing: Eric Evans Interviews Greg Young

I follow Eric Evans (@ericevans0) and Greg Young (@gregyoung) on twitter.  I really respect their opinion and knowledge.

Eric tweeted about an interview he did with Greg over 5 years ago about Event Sourcing.  It’s great to hear Greg describe how Event Sourcing fits with DDD concepts.  This is video is one of the first Event Sourcing + DDD talks that I’m aware of.   I highly recommend checking  it out.

http://www.infoq.com/interviews/Architecture-Eric-Evans-Interviews-Greg-Young

If you are new to Event Sourcing, here is a snippet from Martin Fowler article.

Capture all changes to an application state as a sequence of events.

We can query an application’s state to find out the current state of the world, and this answers many questions. However there are times when we don’t just want to see where we are, we also want to know how we got there.

Event Sourcing ensures that all changes to application state are stored as a sequence of events. Not just can we query these events, we can also use the event log to reconstruct past states, and as a foundation to automatically adjust the state to cope with retroactive changes.