AI writes the code. The catch is your job.
Goodcatch is a code-review practice app. You review real, AI-generated pull requests, write your comments, and get graded on what you caught and what you missed, training the judgment to spot bugs, security holes, and bad calls before they ship.
Catch what matters before it slips away.
The bottleneck in software moved from writing code to reviewing it. AI produces plausible code faster than any team can read it, and plausible is not correct. The scarce skill now is the judgment to catch what the model gets subtly, dangerously wrong. Goodcatch turns that skill into something you can practice, measure, and sharpen.
We now review more than we write.
AI is writing more of the code every day. That means engineers are writing less of it and reviewing far more: pull request after pull request of code a model generated in seconds, waiting for a human to vet it.
So the ability to read code and truly comprehend it, to trace what a change actually does and spot where it goes wrong, matters more than ever. It’s quickly becoming the core engineering skill, and the industry has noticed: more and more tech interviews now test code-review ability directly, not just whether you can write an algorithm from scratch.
That instinct is trainable, but nothing existed to train it. So I built Goodcatch: a place to practice reviewing on real diffs, get honest feedback on what you caught and what you let through, and watch that judgment climb from junior to lead.
Read the diff. Write the review.
Get scored.
Every session is a real PR, reviewed like you would at work, then graded on what mattered.
Read a real diff
A full pull request with surrounding context: production code, real defects hiding in it. Not a toy snippet.
Write your review
Comment on the lines that matter, summarize, and make the call: approve, request changes, or comment.
Get graded
See what you caught, what you missed, and why it mattered, with a score that tracks over time.
Built for anyone who reviews code.
Engineers leveling up
Build the reviewing instinct that senior and staff loops actually test: judgment, not recall.
Candidates prepping for loops
Get reps on the review-style questions senior and staff interviews now ask, with a grade after every one.
Anyone reviewing AI code
When most of your day is vetting machine-written diffs, the catch is the whole job. Practice it deliberately.
The principles behind the grade.
Real diffs, real defects
Every challenge is production-shaped code with bugs that actually hide in review, never contrived puzzles.
Judgment over recall
We reward catching what matters. Nitpicks don’t score, and at Senior and Lead, flagging non-issues costs you, just like a real loop.
Progress you can see
A single skill rating moves with your results and maps to a title, so you can watch the catch become automatic.
Start catching what slips through.
Your first challenges are free, no card required. Grade your first review in minutes.