micronaut

2026-07-06
Every Route Registered. Every Request 404'd.
A registered Micronaut route returning 404 under load. The route matched. The controller ran. Mono.zip ate the response.
The Memory Benchmark · 29/41 6 min read
2026-07-05
The numbers lied until we fixed the ports
Same reactive app on Micronaut, Spring Boot, and Quarkus. The numbers lied until we fixed the harness AND the ports.
The Memory Benchmark · 26/41 7 min read
2026-07-04
Two ways to mistranslate a retry
Porting @Retryable to Quarkus and Spring produced two silent retry bugs. One was a fix that broke parity. Both passed every test.
The Memory Benchmark · 25/41 9 min read
2026-07-02
The Throughput Was Always 115
28 mock APIs. Twelve benchmark scenarios. Two codebases. One number: 115 req/s.
The Memory Benchmark · 19/41 7 min read
2026-06-30
Designed a Reactive Benchmark. Imperative Won.
Built a reactive benchmark with realistic latency. The imperative rewrite survived memory pressure. Reactive didn't.
The Memory Benchmark · 18/41 5 min read
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
2026-06-25
ExecutorType.VIRTUAL Doesn't Exist
The Config Everyone Writes#micronaut: executors: io: type: VIRTUAL Every tutorial. Every "Micronaut + virtual threads" blog post. Every AI suggestion. This is the obvious config. One property, clean intent. It crashes at startup: No enum constant …
The Memory Benchmark · 16/41 4 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
2026-06-17
Loom Carrier on a Reactive Stack: 78 MB for Free
"Virtual threads don't help reactive apps." You've heard this. Probably said it. The reasoning is sound: a fully reactive stack — Mono/Flux from HTTP client through R2DBC to Netty — never blocks a platform thread. Virtual threads solve blocking. No blocking, …
The Memory Benchmark · 11/41 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