Having designed, build and run systems that are deployed on oil platforms all over the world and that use Event Sourcing as their underlying architecture means that I've experienced all the greatness and the pains this architecture style has to offer. In this talk, I'm going to share you my experiences with over 10 years of practicing Event Sourcing in multiple systems. I'll talk about the reasons we adopted it in the first place, the challenges we had introducing this to the developers, the problems we ran into in production, and the lack of confidence we got from management. I'll conclude this talk with my current thoughts on Event Sourcing and how I would implement it when I would have to do it again.