This article discusses the benefits of test sharding, a technique for parallelizing automated tests to improve CI build times without sacrificing software quality. Test sharding involves dividing a large suite of tests into smaller pieces, which can be executed in parallel on different runners, significantly reducing the time it takes to provide developers with feedback on their changes. By employing test sharding, teams can maintain fast cycle times while ensuring high-quality code. The article provides step-by-step instructions for implementing test sharding using Bitrise's out-of-the-box features, including Parallelism and Xcode Test Shard Calculation, as well as scenarios for Android projects that use Gradle's built-in test sharding calculation. By parallelizing tests via sharding, teams can achieve fast CI builds coupled with a high-quality bar, backed by a large suite of unit and UI tests.