Learn how to implement a robust testing strategy for Gatsby sites and apps in this comprehensive 1 hour 32 minute tutorial featuring Kent C. Dodds. Explore essential testing concepts, including the Gatsby Testing Trophy, precommit hooks, and local testing setup. Install and configure Cypress for end-to-end testing, write effective tests that adapt to changes, and create smoke tests. Dive into React Testing Library for component testing, and learn to test subscribed forms and import React elements. Master the process of adding lint rules, configuring test scripts, and troubleshooting common errors to ensure your Gatsby projects are reliable and high-quality.