The things you migrated to JDK 11, can be easily migrated to JDK 15 (or at least 14, if you have some libs depending on Nashorn), the biggest issue with migrati

The things you migrated to JDK 11, can be easily migrated to JDK 15 (or at least 14, if you have some libs depending on Nashorn), the biggest issue with migration was JDK 9 (because of the modules), so if you are past that then it is a breeze.