Can you please dive into specifics a little bit and explain what parts of GitLab could be improved and what are some high-level things that you don't particularly like?
On every other Git repository manager, we can browse source code, view replies to both issues and merge requests without Javascript enabled. But not on GitLab. I don't expect anything advanced to work without Javascript, but these simple operations definitely should and I think it's very bad design to have this requirement. The result of this Javascript overuse is that GitLab is both slower and a bigger pain to use than the alternatives. Use Javascript in small amounts were it make sense for functionality, not just for showing text, pictures or other simple things.
There, my two cents. So, what I meant was that Microsoft should look at GitLab and NOT copy the web interface. GitHub has a nice web interface, with Javascript in acceptable amounts and where it make sense, even the language details bar works without.