It is the dependencies. We bit the bullet and cut over (most) everything to Java 11 last year. Things that were removed from the JDK into new dependencies wer

It is the dependencies. We bit the bullet and cut over (most) everything to Java 11 last year. Things that were removed from the JDK into new dependencies were the easier bits to sort - JAXB, some old Sun classes, and Java EE bits. All that was less than a week to sort. The real work were with the older 3rd party libraries not making the jump. You end up with turtles all the way down in some cases. Those took a serious amount of hunting for replacement. Mind you, the code was almost always something that had no budget or appetite for maintenance, so the moment you had to jump to a new package/API... folks often gave up. All that said - for the 'normal' Springboot applications, we saw almost a 25% performance jump for the same code - updated libraries - running on K8. Java 11 was a substantial performance improvement. The jump for us to Java 17 will happen this winter, and looks to be a non-issue so far.