[simias]

I mentioned FZF (with Rg) with IMO is a great plugin to use. With it you can explore huge projects very quickly without requiring any language specific setup. Vim also supports tags files by default which can be quite nice when browsing large projects, just run universal ctags and you can cross reference symbols for most languages.

Actually the only project-oriented Vim plugins I use are FZF, editorconfig and fugitive (git interface). The rest are just editor tweaks such as vim-unimpaired and vim-surround. And I regularly deal with very large codebases such as the Linux kernel, so at least for my use case it scales reasonably well.