Tekla Perry writes: A year ago Yahoo eliminated its test and quality assurance team, as part of project Warp Drive, its move to continuous delivery of code. The shift wasn't easy, Yahoo tech execs say, and required some "tough parenting." But the result has been fewer errors because "when you have humans everywhere, checking this, checking that, they add so much human error into the chain that, when you take them out, even if you fail sometimes, overall you are doing better." And the pain wasn't as great as expected. Yahoo's chief architect and SVP of science and technology discuss the transition.