Bug Prediction at Google

Every month, 50% of the Google code base changes. This is a lot of code and a lot of people. In order to ensure that its code base stays healthy, Google uses a bug prediction algorithm. This blog post discusses how Google develop this machine-learning and statistical analysis tools that tries to guess whether a piece of code is potentially buggy or not, usually within some confidence range. Bug prediction is not an objective measure by any means, but it is used to place a warning in our code review system on specific files. Whenever a reviewer logs in to review that code, the warning will appear, which hopefully will encourage them to spend some more time reviewing the code or hand off the review to someone more experienced if need be.