### Summary Playwright uses JavaScript promises under the hood, but it doesn't enforce TypeScript type checking or linting, leaving users vulnerable to runtime exceptions and hard-to-spot bugs. By adding TypeScript type checking and linting with `typescript-eslint`, developers can catch common Playwright mistakes before running tests, ensuring safer and more reliable end-to-end testing. The setup involves installing TypeScript, creating a `tsconfig.json` file, and configuring `typescript-eslint` for linting. With this approach, users can avoid unnecessary CI/CD minutes wasted on discovering typos and improve the overall developer experience.