I wanted to see how a fairly representative Java Spring Boot application behaves on a very small VPS, especially the difference between configured heap and actual JVM process memory.

The test app uses Spring Boot 3.5.x, Spring MVC, JPA/Hibernate, H2, embedded Tomcat, Actuator, scheduled work, and outbound HTTP. I also kept lightweight monitoring on the same machine.

The original 256 MB configuration was too tight. With 512 MB RAM + 256 MB swap, the application completed the test reliably.

Full setup and measurements are in the linked article.

Since then I’ve also managed to get the same application working on a 256 MB VPS with swap using JDK 25 Compact Object Headers and tighter JVM settings. I’m preparing that as a separate follow-up experiment.

Wrote a bit about the `unlikely` and `likely` macros in the Linux codebase. Great little exploration into tiny optimizations that everyone should know more about 😄

Android, the last to arrive at the declarative UI party, took its time, until finally reaching a stable solution. Here's a rundown of the major changes in the Android System Design across the eras.

I was away from Android for 7 years and came home to a totally strange place. This is my attempt to make sense of what happened while I was gone - how the stack reset four times (Activities -> MVP/RxJava -> Architecture Components -> Compose) and why each lurch happened. Written for interview prep but the history stands on its own.