To make its developers’ jobs more rewarding, Facebook is now using two automated tools called Sapienz and SapFix to find and repair low-level bugs in its mobile apps. Sapienz runs the apps through many tests to figure out which actions will cause it to crash. Then, SapFix recommends a fix to developers, who review it and decide whether to accept the fix, come up with their own, or ignore the problem.

Engineers began using Sapienz to review the Facebook app in September 2017, and have gradually begun using it for the rest of the company’s apps (which include Messenger, Instagram, Facebook Lite, and Workplace). In May, the team will describe its more recent adoption of SapFix at the International Conference on Software Engineering in Montreal, Canada (and they’re hiring).