Steve Kinney is a US senior software engineer (formerly at Twilio, SendGrid, and Temporal) and one of the long-running instructors on Frontend Masters. He is the author of Electron in Action (Manning) and has taught some of the most cited workshops on web performance, TypeScript, and the testing tracks at Frontend Masters.
His course catalog covers TypeScript in depth (compiler internals, advanced type-system patterns), React (state management, performance, testing), web performance and Core Web Vitals optimisation, the testing tracks (Vitest, Playwright, MSW), and Electron for desktop applications. Material is taught at the level of a working senior engineer rather than a tutorial-grade introduction.
The CourseFlix listing under this source carries over 15 Steve Kinney courses spanning that range. Material is paid; Steve Kinney's courses are primarily distributed through Frontend Masters on the original platform. Courses are aimed at intermediate-and-up JavaScript developers ready to deepen their craft.