Intermediate React, v6: React Server Components, Hooks & Performance vs CSS Grid and Flexbox, v2

v6 is rebuilt around React 19 — render modes, React Server Components both from scratch and inside Next.js, transitions, optimistic and deferred values. Reviewers praise the "under the hood" RSC explanation. The honest caveat is that hooks, TypeScript and Redux content from older versions has been narrowed in favour of the RSC and performance focus.

Brian Holt is the single most consistently praised element across nine years of Hacker News mentions and official testimonials. Learners with one to three years of React experience still call the teaching "fun", "interactive" and clear. Official course rating sits at 4.7 stars.

Requires a Frontend Masters subscription ($39/month or $390/year). At a 6h22m runtime this single course is only worth the price if you pair it with the wider catalog or complete it inside one billing month. Less competitive against the free React docs if you want one course alone.

Unlike the project-based Complete Intro, the Intermediate course is modular — unrelated concepts taught as standalone lessons (RSCs from scratch, RSCs with Next.js, performance demos). Reviewers find the build-from-scratch RSC segment genuinely illuminating, but there is no single cohesive app to carry away as a portfolio artefact.

The RSC and performance material maps directly onto what teams are shipping with Next.js App Router in 2026. Learners specifically credit it with demystifying what Next.js is doing under the hood — transferable knowledge rather than tutorial-only skills.

Covers responsive layout across two parts — Flexbox (grid systems, navigation, responsive images) and CSS Grid (Mondrian and magazine layouts, cards). Reviewers say it teaches modern layout "without hacks", though v2 predates subgrid and container queries.

Jen Kramer is the most-praised element — a long-time CSS educator who explains layout clearly and at a beginner-friendly pace. Learners and a Hacker News commenter call her CSS courses "very good" and her teaching "well taught, in-depth".

Requires a $39/month (or $390/year) Frontend Masters subscription rather than a one-time purchase — strong value if you use the wider catalog, weaker if you only want this one course. The course is included in the standard subscription.

More hands-on than most CSS courses: each section ends in build exercises and a capstone, including a Mondrian painting and magazine layouts. The builds are small practice pieces rather than a full portfolio site, but they reinforce the concepts well.

Flexbox and Grid are the everyday tools for production layout, and learners report finishing real site layouts noticeably faster afterward. The main gap is currency — the newer features (subgrid, container queries) are covered in Kramer's v3, not this version.