That's the trick. You publish the source code. And it's still faster to build all dependencies from source than maven / gradle manages to resolve and download the binary dependencies ;)

That's true, Maven is ridiculously slow to resolve dependencies while Gradle only really works with reasonable speed if you allow it to hog your system with a deamon.

I myself wrote a dependency resolver that matches Maven in functionality, and even a large project that uses Spring Boot and its dozens of dependencies can be resolved in a couple of seconds. About 10x faster than Maven or something like that. If you look at Maven's source code you'll see why. It's the worst kind of Java Enterprise overengineering you can imagine, complete with its own dependency injection framework, everything is pluggable (for no reason, really, do you really need to replace HTTPS for your protocols?? In Plexus you can), to the point that all the de-coupling results in lots of things duplicating functionality everywhere. I am not sure but I would bet Maven parses your POM at least 10 times to do anything due to the de-coupled nature of it.

Maven is actually pretty behind in terms of JVM dependency resolution. Mill uses Coursier, same as my last company did, and when my last company switched from Maven to Coursier we saw a 2 order of magnitude speedup, with resolution commands that used to take 30min finish in a few seconds to give the exact same artifacts and versions.

I actually have no idea why these other resolvers are so slow, or why Coursier is so fast, but this slowness is very much a "maven" or "gradle" thing rather than a "jvm" thing. And Mill using coursier does significantly better!