I just got my projects up to JDK 21 a few months ago. Working on trying to get one upgraded to JDK 25 now and now they're talking about delivering JDK 28 in less than a year from now. How are you supposed to keep up with these rapid updates?
What did you go from to get to 21?
Mostly just hit the LTSes is what we've been doing and since about 17 it's been a pretty easy process in general.
Protip: If you ditch lombok everything gets a lot easier.
How much stuff actually broke? I feel like you can treat Java upgrades as minor upgrades most of the time, maybe you have to rebuild a few binaries but I'd be shocked if it required significant code changes.