reactive

• 2026-06-27
  265 req/s on All Three Runtimes (Until You Add a Memory Limit)

  Native image, JVM, and virtual threads all hit 265 req/s. Then the memory limit dropped.

  The Memory Benchmark · 17/41 6 min read
• 2026-06-20
  We Removed Reactor. Nothing Got Slower.

  We took the entire reactive stack out. R2DBC, Mono, Flux, Reactor Core, loom-carrier, flatMap with its carefully-tuned concurrency arguments. Replaced it with JDBC, HikariCP, and blocking method calls. Same endpoints. Same Netty HTTP server. Same PostgreSQL. …

  The Memory Benchmark · 14/41 5 min read
• 2026-06-15
  flatMap's Second Argument Saved 1.7 Million Requests

  Midway through a code review of the reactive pipeline, staring at this line in NeoService.java: .flatMap(neo -> saveAsteroidWithApproaches(sessionId, neo)) That's Flux.flatMap() with one argument. The function. No concurrency limit. Reactor's default: 256 …

  The Memory Benchmark · 10/41 6 min read