This. I started to get involved in Debian a few years ago (though I'm a long-time user) and this is really really interesting work. There are a lot of packages

This. I started to get involved in Debian a few years ago (though I'm a long-time user) and this is really really interesting work. There are a lot of packages with too little workforce where you can go through a list of dozens or hundreds of bugs. alrs is true ; in most cases your work is automatically replicated to Ubuntu (where the package-maintainer relationship is less strong than in Debian. Most packages don't have a dedicated maintainer there). And everyone can do it ; no sign-up or complicated process required. You just have to find a sponsor for your packages which is just a fancy name for "every code needs review". Debian is often described as bureaucratic but most of the processes are very sane.