Building Watermill: A Journey Through Open Source

Episode notes: https://threedots.tech/episode/history-of-watermill/

Quick takeaways

• Solve real problems first - successful open source projects start by addressing actual needs, not by looking for problems to fit a solution
• Keep breaking changes minimal - Watermill stayed on v1 for 6 years with no breaking changes in the core library, building trust with users
• Examples and documentation are crucial - provide real-world examples with automated tests, not just simple “hello world” demos
• Promotion matters - creating a great library isn’t enough; you need to actively share it through conferences, blog posts, and communities
• Be patient with growth - Watermill took 7 years to reach 8,000 stars; overnight success in open source is rare

In this episode, we share the story of how Watermill, our event-driven library for Go, grew from a side project to a popular open source library with over 8,000 GitHub stars and 100+ contributors.

We discuss the key decisions and strategies that helped make Watermill successful, from focusing on solving real problems to maintaining backward compatibility and building a community around the project.

• Watermill documentation — our open-source event-driven architecture library for Go
• Watermill repository
• Go Event-Driven training that complements Watermill
• Real World Examples