Really interested to give this a try. I haven't used RWX for CI yet (overall my builds wouldn't have benefited enough from the caching), but docker build times are definitely a pebble in my shoe

We use jib at work (https://github.com/GoogleContainerTools/jib) which also skips the Dockerfile and builds an image for a Java project directly.

This certainly looks like a much nicer experience than docker build, especially given that there can be a cache hit after a cache miss.