Event sourcing can be a solution for certain problems in your application, but it also comes with its own set of challenges. One of those is the evolution of your event schema. How should you handle changes to events? Michiel et al. found many approaches while doing research (they published earlier results in their paper “The Dark Side of Event Sourcing”) and they gained a lot of experienced from building a full-size ERP application using CQRS and event sourcing. In this talk he will show what kind of approaches they’ve found and what they used to deal with our specific challenges. He will also share early research results from interviews with over 20 different companies using event sourcing. Every request for advice can be answered with ‘it depends’, and this talk will not solve that. But he will tell you what your options are, what he think works, and what many others have done.