What events should my component publish? Not always an easy question to answer.

Software design is a continuous task. You never finish a software project, because it needs to evolve as the team’s knowledge about the problem it solves grows. This is why one of the principal characteristics of good software is being easy to change.

In an asynchronous software architecture, the events that a component publishes define its contract with the other components in the system. And a good interface contract is one that lets the component be useful to the other components, while making it easy enough to modify as the project grows.