[giomasce]

By my experience, it helps a lot to have a handful of patches in Wine already. Doesn't have to be anything especially great, but showing that you can work with the conformance tests (both write them and fix them), create good commits, go through the patch review process, interact constructively with the maintainers can get you a lot of points and make up for a not necessarily perfect interview test.

Do not look for the super-core stuff like user32.dll and ntdll.dll. There is already a lot of folks working there and it's hard to make an improvement if that's your first contribution. But there are a plethora of random forgotten libraries in dlls/ which usually nobody cares about until some application depends on those, and they are quite likely to have a good amount of low hanging fruits. Look for the todos in the tests, for example.

Disclosure: I work for CodeWeavers, but I am not involved in the hiring process.