At Uber, we obsess over delivering highly performant and reliable experiences to our partners and customers. We treat degradations to app performance the same way as any other functional regressions. Before investing effort into improving performance and reliability, we need to understand how our app is performing in production. We use various tools to derive metrics that allow us to measure app performance and reliability. We also establish baselines to ensure that new feature development is consistent with the high bar we hold for performance and reliability.