On average, I’m doing just under four totally automated zero-downtime production deployments per day since I started doing continuous deployment on this project in early August 2011.
Obviously, that’s an average, so some days there are more, and some days there are fewer.
How many times during that span has improperly tested code broken things in a way that impacted users? Just once, and it was fixed in just a few minutes by adding back the code that I over-zealously removed.
Also in that time, we went from 0% automated test coverage to 18% automated test coverage, refactored a lot of duplicate code, and added new features.