OK, just some jolly benchmarks moving from "serially building all docker containers with a build script" to "parallel builds using pants": we went from 28.8 minutes (1730 sec) to 611.88 seconds, about a 2.8x improvement (and there's one spectacularly long-build container that's responsible for the long tail; most were built much faster so if it weren't for that laggard this would look much better). And that's not even counting the impressive dependency checking, etc that goes with a proper build system. Very pleased with this; going to be working on moving it to production. Thanks for the fantastic support!