Stop Using Spring Boot to Build Microservices.⏱️

Spring Boot was built for rapid monolithic and enterprise web applications. But when you break your architecture into fine-grained microservices, the old tools don’t fit the new world.

Micronaut is built from the ground up for microservices — lightweight, fast, and born cloud-native.

Let’s focus on the differences that matters

⚡ Startup time matters

• Spring Boot applications often take several seconds to start because of runtime classpath scanning and reflection.

Started App in 4.678 seconds (JVM running for 5.012)

• Micronaut processes everything at compile time, starting in milliseconds — even on cold starts.

Startup completed in 890ms.

Micronaut boots in <1s, even on cold start.

🧠 Memory is money

• Spring loads tons of metadata into memory at runtime.

Used heap: ~120MB for a simple REST service

• Micronaut skips the runtime guesswork and minimizes memory by calculating dependency graphs at compile time.

Used heap: ~12MB for the same REST service

90% less memory usage out of the box.