GitHub Contributor

We are looking for senior-level engineers with a visible open-source track record to help train AI systems on real code. You will create reinforcement-learning environments from real repositories, with reproducible setups and reference solutions.

Key Responsibilities

• Build tasks from real repositories that test whether an AI model can fix bugs, add features, refactor and improve performance.
• For each task, provide a reproducible environment and a reference solution.
• Investigate and resolve difficult defects and performance bottlenecks in varied code bases.
• Refactor legacy code for clarity, efficiency and long-term reliability.
• Write up your technical reasoning and code decisions to raise training-data quality.
• Follow project guidelines, take part in calibration and review sessions, and incorporate feedback to keep quality consistent.

Required Qualifications

• A clear public record of open-source contributions (GitHub or GitLab profile).
• 3+ years of software engineering experience.
• Strong skills in Python, Java, Rust, Go, C++ or TypeScript.
• Experience with Git, Docker and automated testing.
• Fluent written English.
• Reliable, detail-oriented, and able to work independently and meet deadlines in a remote setting.

Preferred Qualifications

• Project maintainer or core-contributor experience.
• Experience with large or distributed code bases.
• Code-review experience.

Rights, Confidentiality and Data Handling

• Submit only work that you created yourself or that you have the right to share.
• Do not submit material covered by an employer, client or third-party confidentiality agreement, or material you have no right to share.
• Do not submit export-controlled, military or defence-related technical data.
• Remove credentials, secrets and personal data from anything you submit.
• Rex may ask for evidence of ownership or licence, may verify submissions, and may reject or remove any submission.

Legal and Compliance Notice

• All content you submit must be lawful, and you must have the right to share it.
• Do not submit confidential or proprietary material belonging to an employer, client or third party, or personal data without a lawful basis.
• Rex may verify identity, credentials, ownership and licensing; may reject or remove any submission; and may report unlawful submissions to the relevant authorities.
• Engagement and payment are subject to successful verification and to applicable sanctions, export-control, tax and employment laws.
• The contractor agreement will set out ownership and licence terms for the work you deliver (to be confirmed by Rex Legal).

Where you can work

This role is 100% remote: you can work from anywhere in the world.