In this episode of The Bootstrapped Tech Founder, Lucas and Luna explore how bootstrapped software founders use open-source projects not just as a marketing tool, but as a direct revenue channel. They unpack the story of Sidekiq, a background processing library for Ruby that grew to over $6 million in annual recurring revenue without a single venture capital dollar, by selling a commercial version alongside the free open-source core. Lucas explains the 'open core' model, the risks of misjudging how much value to give away, and why charging for operational simplicity works better than charging for features. Luna pushes back on whether this model is viable for consumer-facing tools, and they land on a framework: open source builds trust and distribution, and the commercial tier should solve pain, not lock essential functionality. No ads on this show, so if you value that, you can support at buy me a coffee dot com slash fexingo. If you're building a bootstrapped product, this is one of the most capital-efficient growth strategies you'll find.