In a blog post by Gleb Bahmutov, the author discusses optimizing test speed in Cypress by identifying where tests spend the most time. The focus is on measuring the duration of individual Cypress commands to pinpoint slow commands, such as cy.type and cy.click, which involve server communication and consequently take longer. Bahmutov demonstrates using events emitted by the Test Runner to capture command durations and suggests stubbing network calls to improve speed, though this doesn't always yield expected results. He explores the impact of keyboard events on typing commands and offers a solution by using blur events to equalize command durations. The post concludes with advice on using fixture files for focused testing and illustrates how to print test duration and command timings in the terminal during Cypress runs, ensuring both efficient and effective testing practices.