Spring annotations in general. There's a completely hidden bean context where every annotation seems to throw interceptors, filters, or some reflection crap into. Every stacktrace is 200 lines of garbage, every app somehow needs 500mb for just existing and if you add something with a very narrow scope, that suddenly causes something completely unrelated to stop working.

Realistically, DI and all the Spring crap does not add anything but complexity.

Holy shit mood, described to the tee.

An application I've never heard or seen before that needs to be upgraded, and it breaks, so you now need to understand what the hell this application does so you can fix it properly.

Gradle, with it's transitive dependency modifications is a huge pain in this area.

It used to be that if a library ended up having a flaw then it would be flagged and we would get the dependency updated. These days security block the "security risk" and you have to replace your dependencies dependency. Fingers crossed you can get it to actually test all the code paths.

If an second level project gets a flaw, and it's used indirectly then we should really look at getting the import updated so that we know it works. If that import is abandoned then we should not be updating that second level dependency, either adopt and fix the first level dependency or look at an alternative.