Every Spring Boot project I touch eventually grows a .env, an application-local.yml, or some secrets.properties that I'm told to "just not commit". It's convenient: one file, all your local keys, sourced in seconds.

But here's the catch: that file is plaintext, and it sits on disk. Anything running as you can read it — a misbehaving build plugin, a backup daemon, or, increasingly, a coding agent you let loose in your repo. Putting a sensitive API key or a production-adjacent DB password in there is something I'm not comfortable doing on my daily driver.

AI-powered code generation CLIs like Claude Code, Gemini CLI, OpenAI Codex, and GitHub Copilot are incredibly productive tools. They can scaffold projects, refactor code, and even run bash commands on your behalf.

But here's the catch: they can also hallucinate. And a hallucinated rm -rf or a runaway npm install that fills your disk is not something you want happening on your main OS.

Spring Boot testing library offers an out-of-the box @SpringBootTest annotation that boots the entire application and gets it ready for testing.

However, getting backing services (e.g. databases, caches, message brokers) available and not interfering with development or other environments might still be a challenging task.

It's good, tempting, it comes instantly, but on a long run it will most probably cause some issues. What are the similarities when it comes to building applications?

There are many options when it comes to which framework to use for developing JVM-based microservices these days.

In this post, I'm going to summarize how they perform on two simple day-to-day scenarios (with some variations) from wrk's point of view.

It's good, tempting, it comes instantly, but on a long run it will most probably cause some issues. What are the similarities when it comes to building applications?

Spring allows us to publish ApplicationEvent instances using the managed ApplicationEventPublisher instance.

Each such ApplicationEvent can be consumed by the interested parties by annotating methods with @EventListener or @TransactionalEventListener.