The Last Algorithms Course You'll Need vs Modern React with Redux

Across roughly nine hours and 60 lessons the course covers Big O time and space complexity, arrays, linked lists, queues and stacks, a ring buffer, recursion, the classic searches and sorts (linear, binary, bubble, quick), trees with BFS and DFS, heaps, maps, graphs with adjacency lists and matrices, and Dijkstra's shortest path. Reviewers repeatedly call it content-dense and "not the typical watered down content you find often on online courses." The honest mark-down is that it is implementation-first and fast — it condenses a full-semester CS course into under ten hours, so it favours breadth and live coding over slow, proof-heavy depth.

ThePrimeagen is the reason this course is so widely recommended. Reviewers describe his explanations as "full of joy and charisma," call him "an excellent communicator" who is "both down-to-earth and incredibly skilled and intelligent," and note that "you won't get bored and fall asleep." He implements most algorithms live rather than showing finished code, which learners consistently single out as the high point. This is one of the most engaging instructors in the DSA space and it shows in the 4.9/5 rating.

The course is completely free — all you need is a free Frontend Masters account — yet it sits behind, and is the same quality as, Frontend Masters' paid catalogue. For roughly nine hours of well-produced video plus a bespoke practice tool, reviewers call it "a worthy investment" and say "there is no other algorithm course that can teach you so many topics in such an efficient way." The only caveat on value is the subscription framing: the deeper Part 2 (advanced algorithms) sits behind a paid Frontend Masters subscription.

The standout practical feature is the kata-machine, a bespoke GitHub repository ThePrimeagen wrote that generates a fresh daily set of algorithm exercises with a ready testing environment, so you implement each structure from scratch in TypeScript rather than just watching. Learners praise this as the thing that makes the knowledge stick. The caveat is that there is no graded capstone or certificate, and some implementations (notably the doubly linked list) are "complicated, or rather convoluted, to implement," which can stall practice.

The stated goal is to teach enough DSA that, after practice, you could pass interviews at a large tech company, and reviewers report it delivered exactly that mental model — one four-year professional said "this was exactly what I needed to get back on track." The patterns (Big O reasoning, BFS/DFS, Dijkstra, the common sorts) are the bread and butter of coding interviews. But it is a foundation, not a credential: there is no certificate, and complete beginners will need significant outside practice before the interview goal is realistic.

The standout is Grider's diagram-driven explanation. Reviewers repeatedly praise how he explains everything "bit by bit" with custom mockups and visuals, and deliberately walks through common mistakes before the preferred fix. The catch: at 75+ hours some sections cover older class-component and legacy Redux material learners no longer need.

Grider is one of the most consistently praised instructors on Udemy. Across blogs and Hacker News, developers call his courses "outstanding" and say his style is exceptionally clear. The 4.7 Udemy rating across ~89,000 ratings reflects this. The only recurring note is that his slow, thorough pace does not suit everyone.

On Udemy's frequent sales (~$15), 75+ hours of well-structured, frequently updated content is a strong deal, and reviewers say it is "worth every penny." It still loses a little because part of that runtime is legacy material, so the effective value is high but not every hour is essential.

The course is hands-on and project-based, which most learners value. But the most common criticism is that it lacks real challenges — the projects are largely follow-along, with no exercises where the student must implement features alone. Some also flag unexplained Bootstrap styling that complicated their own later builds.

It covers modern, employable React — hooks, Context, React Router, TypeScript, and Redux Toolkit in recent updates — and developers report it genuinely prepared them. The honest gap is depth on testing and the lingering legacy Redux sections, which can leave beginners unsure which patterns are current.