Open source
Fixes I sent upstream, and code you can read
Most of my work lives in private client repositories. These are the parts anyone can check: pull requests merged into widely used libraries, public fixes made during client work, and my own open-source projects. Star counts as of October 2026.
Last updated:
Merged into the original projects
- cssnano #744, 2019. I fixed a crash in cssnano, the PostCSS-based CSS minifier maintained by its community (about 5,000 stars): merging border properties failed when a border width was missing, and my guard for that case was merged by the maintainers.
- p‑queue #69, 2019. I added the missing main field to package.json in p‑queue, Sindre Sorhus’s promise queue (about 4,300 stars), so tools that resolve a package by that field can find its entry point. Merged.
- react‑image‑crop #417, 2021. I added React 17 support and fixed endless re‑renders inside modals in react‑image‑crop, Dominic Tobias’s image cropping component for React (about 4,100 stars). Merged.
Public fixes from client work
Done during paid work for clients, and public because the code was public.
- Sage, Carbon #5947, 2023. During outsourcing work for Sage I fixed the published package of Carbon, Sage’s open-source React component library: a file one of its scripts needed was missing from it.
- Omio, ad libraries, 2021 and 2022. At Omio I fixed the ad libraries the product ran in production, in their forks. In a fork of NFL’s react‑gpt I fixed race conditions on updates and allowed early size mapping setup. In a fork of NZME’s react‑native‑ad‑manager I added fluid native ads on Android, with detection by ad size and by app events, and made ads fail‑safe so they can no longer crash the app.
My projects and main contributions
Both profiles are mine: przemyslawzalewski for work and client contributions, Ciunkos for my own projects.
- Korona Krulów. A satirical browser game in React built in two weeks of evenings in 2020, played by 100,000+ people, with its code on GitHub.
- Agent skills. Skills for Claude Code, Codex and ChatGPT, including /przemo and /indexnow.
- Contact forms tutorial. A small tutorial on contact forms with nodemailer and React, about 30 stars.
- std. Sanddev’s open-source library of typed everyday functions, used across its projects. I moved it from JavaScript to TypeScript in 2019 and was its main contributor.
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Calls this week · work starts 3 November 2026 · B2B contract · Wrocław, Poland (CET), remote
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