> wouldn't just running processes be just as fast The applications we test with this system have dependencies, both system packages and datastores. Containers

> wouldn't just running processes be just as fast The applications we test with this system have dependencies, both system packages and datastores. Containers allow us to isolate the test process with all the dependant datastores (MySQL, Redis, ElasticSearch, etc) If we were to use regular processes we'd both have to ensure the environment is properly setup before running the tests, and also fiddle with tons of port configurations so we can run 16 MySQLs and 16 Redises on the same host. See my other comment for more details https://news.ycombinator.com/item?id=12366824 https://news.ycombinator.com/item?id=12366824