I tried the Quarkus version, but it does some kind of build step at container startup, and that is what used the most memory.

You can apparently build an "optimized" image[1] so it doesn't do it at runtime, but I didn't want to build a custom image, and I felt like the KeyCloak philosophy didn't align with my own.

In general I found myself avoiding Java applications because of their memory footprint.

[1] https://www.keycloak.org/server/containers#_creating_a_custo...