The seventh part of the course covers several topics. We begin by looking at how to define custom hook functions. After that, we explore how bundling works in React applications: we get acquainted with esbuild as a low-level bundler and look at how Vite can be configured for different scenarios. Toward the end of the part, we briefly cover class components and other React development topics such as code organization and error boundaries.

Part updated April 7th 2026

• React router, UI libraries and Styled components moved to part 5
• Webpack replaced with esbuild
• Error boundaries and keeping the frontend and backend in a single repository covered
• Some of the exercices changed, couple of new ones added