Watch the algorithm run.
Then walk into the interview.
Paste any LeetCode problem and codebrew builds an interactive, step-by-step lesson — trace every variable, watch the pattern move, and drill it with instant feedback.
↑ a real lesson, stepping through Longest Substring
Built for the interviews at Meta · Google · Amazon · and everywhere else
LeetCode shows you the solution. It never shows you why it works.
Reading an accepted solution is not the same as understanding it. You can follow every line and still freeze when the pattern shows up under a different name.
- A wall of finished code you scroll past
- An editorial you read once and forget
- No idea which variable changed, or when
- You memorize this problem, not the pattern
- Watch the algorithm execute, one step at a time
- See every variable and pointer update live
- Learn the pattern behind the problem
- Prove you get it with instant AI feedback
Three steps from stuck to fluent
Paste a problem
Drop in any LeetCode URL, search by name, or describe your own. A lesson is generated in seconds — no setup.
Watch it run
Step through the algorithm with the right visualizer for the pattern: trace tables, DP grids, sliding windows, graph traversals, and more.
Practice & prove it
Work guided checkpoints and get instant, specific feedback from the AI grader — until the pattern actually clicks.
A lesson, not a spoiler
Everything is built around one idea: you should be able to watch the solution happen and then reproduce it yourself.
20+ interactive visualizers
Trace tables, DP grids, binary search, two pointers, BFS/DFS on trees & graphs, monotonic stacks, heaps, union-find, backtracking trees, intervals, and more — each matched to the pattern.
Variable-level tracing
See exactly which pointer moved and which value changed at every step. No more guessing what the loop is doing.
AI practice with feedback
Guided checkpoints grade your reasoning and code with specific, actionable feedback — active recall, not passive reading.
Saved notes & highlights
Mark the insight that made it click and keep your notes on any lesson to come back to before the interview.
Interview tracks
Curated study plans that build pattern by pattern, with progress tracking so you always know what's next.
Pattern-first learning
Every problem links to the underlying pattern, so you learn the transferable idea — not just this one question.
Start from the pattern that's giving you trouble
Every pattern has a deep-dive page and a set of representative problems. Pick one and generate a lesson in a click.
Popular problems
Don't know where to start? Follow a track.
Curated, pattern-ordered plans that take you from the fundamentals to interview-ready — with progress tracking along the way.
Start free. Upgrade when it's paying off.
Premium
$6.99/mo
- Unlimited lessons
- Notes, highlights & sharing
- Tracks with progress
Questions, answered
What does codebrew actually generate?+
For any problem, codebrew builds a full interactive lesson: an explanation of the pattern, a step-by-step visualizer you control, the key insight and complexity, and guided practice checkpoints with instant feedback.
Do I have to paste code, or just the problem?+
Just the problem. Paste a LeetCode URL, search by name, or describe a custom problem in plain English. codebrew figures out the right approach and the right visualizer for it.
How is this different from a solution video or editorial?+
A video plays a fixed explanation at you. codebrew lets you drive: step forward and back through the algorithm, watch each variable change, and then prove you understood it by working the practice checkpoints yourself.
Is it really free?+
Yes — you get 3 full lessons per day free, including every visualizer and practice mode, no signup required to try it. Premium removes the daily limit and adds notes, sharing, and interview tracks.
Which problems are supported?+
All of LeetCode plus anything you describe yourself. We also maintain deep-dive pages for 14 core patterns and 51+ of the most common interview problems.
Will this help me in real interviews?+
That's the whole point. codebrew is built around patterns and active recall, so you learn the transferable idea behind each problem instead of memorizing one solution — which is exactly what a novel interview question tests.
Stop memorizing solutions. Start understanding them.
Paste a problem and watch it run. It takes about ten seconds to see why this is different.