Debug code you didn't write.
That's the whole job. Fix a real ticket in a working repo, open a pull request, and a human tells you whether it would have merged.
- projects
- projects
- tickets
- tickets
- levels
- 4 levels
- review time
- 24h review time
One is in the catalog right now — find the bug
Token bucket denies a request that exactly matches remaining tokens
A bucket of 10 serves 9 requests and rejects the tenth.
Click the line that causes it
The real file is longer. This is the part that matters.
Nobody's job is reversing a linked list.
Puzzle sites train pattern-matching on isolated problems. Real engineering is reading unfamiliar code, forming a theory, and proving it inside a system you didn't write. That second skill is the entire gap between a good engineer and the one everybody calls when production is on fire.
What a puzzle site rehearses
- Recognise a problem shape you have drilled before
- Write a function into an empty file
- Turn the hidden tests green
- Work alone, against a clock
What a ticket asks for
- Read a system nobody has explained to you
- Change one thing without breaking the four next to it
- Meet acceptance criteria a person wrote and a person checks
- Convince a reviewer your theory was right
The loop
Four steps, then repeat.
These are the actual commands. Copy them now if you want to see where this goes.
“10x isn't a personality type.
It's a rep count.”
Difficulty grows the way the job does.
Every project runs the same four rungs: fix a bug, ship a feature, make it fast, then make it clean. Start where you're comfortable and climb.
Projects
Start with one of these.
$git checkout -b fix/your-first-bug
Pick a ticket.
See how far you get.
Free while we're in early access. No sandbox to fight and no puzzle to reverse-engineer. A real codebase, a real ticket, and a human who reads your diff. Rep one starts here.
- Reviewed by a human, usually within a day
- Work locally, in your own editor
- No credit card, no trial timer