In a new post on his Medium Blog, maintainer Dries Vints wrote how he managed do drastically improved the build time of the popular forum.

CircleCI 2.0’s builds run with Docker which makes spinning up new instances super fast. If you use pre-built images which are customized to your needs, you don’t even need to do any provisioning during the build which saves you quite a bit time. Pulling various images and orchestrating them in a CircleCI 2.0 config allows for very rapid build times. If you add their new workflows to their mix you could easily enable parallelization and speed things up even more.