With HeadSpin Nimble we detected ~30 slowdown regressions over the course of six months. Since our alert threshold was 100 milliseconds, these regressions, if released to our production app, would have accounted for at least three seconds of additional wait time. Aggregated over the hundreds of millions of actions taken each day, it had the potential to be a significant amount of time wasted. By catching regressions early in the cycle, they were never released to Pinners.