[mhitza]

Most, let's call it, web software is a handrolled system with its own framework, design patterns, etc. Flarum is a great example of web software that rolled it's own, WordPress is another far more popular piece of software that does it's own thing.

The point being, that unless you're already familiar in the "system language" of the software you want to hack upon, or unless the software is very light on abstraction, it's gonna be pretty inconvenient to MVP on top of it.

I've tried in the past to take that approach with few small projects and gave up pretty quickly. In my view it's the same as getting onboarded on a new project - it's slow. The only difference is that with OSS software you might have a bit more documentation available