Git itself isn’t though, not in any real way that matters. Having to know all the sub trees to clone in a mono repo is a usability nonstarter. You need a pseudo

Git itself isn’t though, not in any real way that matters. Having to know all the sub trees to clone in a mono repo is a usability nonstarter. You need a pseudo filesystem that knows how to pull files on access. And one ideally integrated with the build system to offset the cost of doing remote operations on demand and improve parallelism. Facebook is open sourcing a lot of their work but it’s based on mercurial. Microsoft is bought into git but afaik hasn’t open sourced their supporting git tooling that makes this feasible. TLDR: the problem is more complex and pretending like “you can checkout a subtree” solves the problem is missing the proverbial forest for the (sub)tree