While I’ve been giving talks at conferences and user groups for the last decade, I leveled up a little on Friday and was an invited speaker on the Vassar College Computer Science Asprey Lecture Series. The topic was Software Engineering at Scale, using the OpenStack project as an example.

I gave the folks there a glimpse of what’s behind a successful project that is able to integrate code from over 400 unique developers in 5 months time. I talked about planning, the design summits, the contribution and code review tools we use. But, as with every time I talk about OpenStack, the thing that really wows people is the testing infrastructure we’ve got. It was equally latched onto by the students and CIS staff in the room.

On every code submission we run style checks, unit tests (5000 of them in Nova now), and spin up a full OpenStack install and hit it with a nearly 700 test integration suite, before the first humans start looking at the code for manual review. It’s an incredibly empowering system, that means developers have a high bar to submit working code that doesn’t alter the behavior of the system. And it means that by the time the expert eyes do code review, the kinds of problems they are looking for are much more interesting.

Just this morning it meant I could look through a new proposed extension in gerrit and focus on some of the functional behavior, including understanding which kinds of code the test system has a harder time touching. The confidence that gives you as a reviewer that everything isn’t on the verge of breaking all the time, is enormous.

I’ve submitted a similar talk to the OpenStack summit, with a slightly different perspective of educating new developers on what the process from idea to code landing in the OpenStack tree is. Hoping that gets selected as it should be a good talk, and give me an excuse to polish some of my code flow diagrams a bit more.