Gleb Bahmutov's blog post outlines a method to optimize the testing process for large projects with numerous Cypress spec files by prioritizing the execution of changed spec files in a pull request. This approach allows for faster identification of new issues introduced in the code changes by running the modified spec files first, followed by a complete run of all specs to ensure no additional bugs have been introduced elsewhere. The implementation utilizes GitHub Actions and Git commands to automate this "double run" continuous integration workflow. Bahmutov provides detailed instructions for setting up a GitHub workflow that fetches and checks out branches, identifies changed spec files within a specified directory, and executes them using Cypress. By integrating with the Cypress Dashboard, the workflow can record test results for easy debugging. Additionally, the blog post addresses why this functionality is not directly integrated into the Cypress test runner, citing the overhead of maintaining new features as a consideration.