125 Java Concurrency

This is a comprehensive concurrency review checklist for Java codebases that won't let you proceed if your project doesn't compile first, which is a sensible guardrail. It covers the full spectrum from basic thread safety primitives like ConcurrentHashMap and AtomicInteger through to modern virtual threads and ScopedValue. The workflow is straightforward: compile, read the reference for good and bad patterns, apply improvements, then verify. What makes this useful is the breadth of coverage, including less common concerns like false sharing, virtual thread pinning detection via JFR, and backpressure strategies with bounded queues. If you're doing any serious concurrent programming in Java beyond trivial thread pools, this gives you a structured way to audit your approach against current best practices.