...The course then adds composition, routing, class state, error boundaries, context, portals, and refs. Intermediate sections examine Redux, code splitting, server-side rendering, Tailwind CSS, testing, and TypeScript migration. A separate companion repository provides incremental project snapshots for each major lesson. The material also covers supporting tools such as npm, Parcel, Babel, ESLint, Prettier, and browser development utilities. Because it reflects an earlier React ecosystem, it is best used as structured courseware rather than a current starter template.