About If you are using ClojureScript (and if not, why not? :-)) then I *strongly* recommend you enable parallel build. I mistakenly thought this meant that it would run separate builds in parallel, but no, it is far cleverer and more useful than that, it builds a single build in parallel. Also, to be crystal clear, this isn’t going to do anything to your runtime performance, only the build time. ... Read more

Another quick tip. I use the excellent cljsbuild to compile and test our ClojureScript projects (and I can’t believe how difficult it is to wire this stuff together in 2016!). To support continuous integration I use phantomjs to provide the JavaScript environment. Unfortunately circleci’s environment doesn’t have phantomjs v2 available to it and v1 has some troubling properties. It turns out, after much googling and dead ends, that it is pretty trivial to get phantomjs in your circleci environment, simply add: ... Read more