[vbezhenar]

IBM WebSphere Application Server took several minutes to start or stop. Deploying war file took another 10-30 seconds. And you had to restart application server sometimes.

Spring Boot application with few controllers starts in 2 seconds on my outdated laptop.

Spring is lightweight, compared to old tech.

Not the most lightweight, that's for sure. Simple Java web server which uses socket API to server requests, starts in few milliseconds. That's the bar.