GitHub Contributor

Overview

Rex is looking for senior-level engineers with a visible open-source track record to help train AI systems on real code. The work involves creating reinforcement-learning environments from real repositories, with reproducible setups and reference solutions.

What You'll Do

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

Who They're Looking For

• A public open-source contribution record on GitHub or GitLab.
• At least 3 years of software engineering experience.
• Strong programming ability in Python, Java, Rust, Go, C++, or TypeScript.
• Experience with Git, Docker, and automated testing.
• Fluent written English.
• Ability to work independently, meet deadlines, and stay reliable and detail-oriented in a remote setting.

Preferred Qualifications

• Experience as a project maintainer or core contributor.
• Experience with large or distributed codebases.
• Code review experience.

Rights, Confidentiality, and Data Handling

• Submit only work you created yourself or that you have the right to share.
• Do not submit work covered by employer, client, or third-party confidentiality obligations, or material you do not have the right to share.
• Do not submit export-controlled, military, or defense-related technical data.
• Remove credentials, secrets, and personal data from anything you submit.
• Rex may ask for proof of ownership or licensing, verify submissions, and reject or remove submissions if needed.

Legal and Compliance

• All submitted content must be lawful and shareable by you.
• You must 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; reject or remove submissions; and report unlawful submissions to relevant authorities.
• Engagement and payment are subject to verification and applicable sanctions, export-control, tax, and employment laws.
• The contractor agreement will define ownership and licence terms for delivered work, subject to Rex Legal confirmation.