Need For Iteration Speed 📎
I noticed that coding agents reach for Quarkus developer mode by default. They start quarkus:dev and keep it running.
An agent edits, then it has to observe the result before deciding the next move: compile error, test verdict, endpoint response.
- Live reload on the next request. The agent edits a resource. The system tests, running on a second Quarkus in Dev Mode, hit the live-reloaded endpoint over HTTP and report back. No rebuild, no restart on either side.
- Continuous Testing. Tests re-run on the affected code automatically. The agent gets red or green without asking for it.
The math is simple. A thirty-second restart is an annoyance for a developer who hits it five times an hour. For an agent iterating two hundred times, it is the entire budget. Cut the loop to a second and the agent spends its time changing code instead of waiting for the JVM.
The continuous-testing skill at airails.dev encodes this loop: after every change it builds, starts the server, and runs the unit, integration and system tests.
Fast iteration was always the point of Dev Mode. Agents just run into the payoff far more often than people do.
For java-cli applications there is no Dev Mode, but zb builds them so fast (< 1s) the loop stays just as tight. Another excuse to use it. 😀