Ruby gem by Evil Martians (the speaker notes its name intentionally avoids 'TestProf' branding). Large toolkit of solutions for test-suite slowness. Most popular features: detecting and profiling Factory Cascades (identifying which factory and which test are slow), converting create calls to build automatically and logging which tests then fail so they can be rolled back, and catching factories to reuse them as fixtures. Pairs with the 'aggregate failures' RSpec feature the talk recommends for slow endpoint tests.