Christie Wilson/Michael Tom-Wing - System Testing with pytest and docker-py System tests are an invaluable tool for verifying correctness of large scale online services. This talk will discuss best practices and tooling (pytest and docker-py) for writing maintainable system tests. Demonware has used System tests to verify online services for some of the biggest AAA video game launches as well as internal operational tools. Many folks who write software are familiar with unit testing, but far fewer with system testing. ----- System testing a microservice architecture is challenging. As we move away from monolithic architectures, system testing becomes more important but also more complicated. In the video game industry, if a game doesn’t work properly immediately after launch, it will heavily impact game success. We have found system testing to be an important tool for pre launch testing of game services and operational tools, to guarantee quality of these services at launch. We want to share with you best practices for system testing: when to write system tests, what to test and what not to, and common pitfalls to avoid. Using python’s pytest tool and docker-py for setting up services and their dependencies has made it easier than ever to write complex but maintainable system tests and we’ll share with you how we’ve made use of them. Developers (senior and junior) and ops folks can walk away from this talk with practical tips they can use to apply system testing to their software.