How Long To Run an A/B Test as a Bayesian

Important This blog post is inspired, almost entirely, by Tyler Buffington’s excellent statistics reading group presentation today at Datadog on the value of information in A/B testing. The ideas presented here are mainly his, I’ve just gone ahead and done a little more math. I’ve also relied a lot on AI to help me get through some of the math. I can’t remember all the tricks there are for…