Modern Java Runtime, Threads, and Concurrency

Trace a backend request through stack frames and heap objects to identify thread-confined and shared state.

Explain generational garbage collection and interpret basic pause-time and allocation-rate metrics.

Distinguish atomicity, visibility, and ordering guarantees in the Java Memory Model.

Reproduce and diagnose a race condition in shared mutable Java state.

Protect a compound state transition using synchronized blocks or explicit locks.

Select an appropriate concurrent collection for a specified read-write workload.

Execute independent I/O operations with CompletableFuture and propagate failures correctly.

Configure and compare a bounded platform-thread executor with a virtual-thread-per-task executor for a backend workload.