Advances in the java programming language, version 16 and newer, slashed a million lines of code from my codebase. Maintaining my programs became easier overnight, due to this 1 secret trick: Records. 
Unfortunately version 16 was not LTS, so I had to wait until this year’s release of version 21, which is LTS. 
 Go read the linked article. It explains Java Records in a very approachable manner.