Modern Java (21+)

Write, review, and refactor Java the way the language is shaped today, not the way it was in 2014.

Targets Java 21+ with Java 25 as the current LTS (released 2025-09-16, supported to 2033; Java 26 is the current non-LTS, 2026-03-17). "Modern" here means: records and sealed interfaces instead of JavaBeans and type hierarchies, exhaustive pattern-matching switch instead of instanceof+cast ladders, virtual threads instead of hand-tuned pools, and ScopedValue instead of ThreadLocal. If you are reaching for a telescoping constructor, a getter/setter bean, or a manual ExecutorService sized to a core count, stop.

When to use / When NOT to use

Use when: