CPU-bound endpoint (/cpu, 20,000x SHA-256), concurrency=60, 2 vCPU sandbox, Spring Boot 4.1.1 / JDK 25.0.4.1
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platform threads : total=60 success=60 wall=208ms p50=130ms p99=202ms
virtual threads  : total=60 success=60 wall=201ms p50=187ms p99=196ms

a CPU-bound virtual thread never yields -- it stays mounted on its carrier for the full
computation, so it competes for the same 2 physical cores a platform thread would. Expect
these two wall times to be close, not virtual threads winning decisively as in the I/O case.