Software that notices the bug you missed.
We write small tools for finding mistakes in code. They are free. We started in Warsaw in 2025, after one too many dashboards that only showed a green check.
Try a diff
Sample only. Nothing is uploaded.
41if (user && user.email) {42 send(user.profile.timezone)43}
Lintbox has not looked at this yet.
What we ship
Lintbox
A command-line checker. Point it at a pull request and it marks the few lines most likely to break. It is often unsure, and it says so. MIT license. No account.
Nightwatch
Runs the tests you already wrote, after hours, and mails you only when a failure is new. The mail is plain text. There is no dashboard.
Drift
Compares config between staging and production and lists what quietly changed. One binary. Free since the first week, because invoicing took longer than the bugs.
Notes
12 Mar 2026
Drift 1.4. Still free. It now ignores comments in yaml.
2 Nov 2025
Nightwatch stopped posting to chat. Mail only. Fewer false alarms.
18 Jun 2025
Lintbox 0.9, first public build. Written in a flat in Praga.
Two engineers, third floor of a tenement in Praga. If a tool is useful it stays public. If it isn’t, we delete it. Nothing here needs a signup.