Open Source Maintainer / Core Contributor at Mercor

Open Source Maintainer / Core Contributor | $150/hr | Remote (US)

Join a leading AI lab's GenAI team and help improve AI training data for software engineering, code review, and open-source maintenance. This is a full-time W-2 position with Cincinnatus LLC, an enterprise staffing company, with placement at a leading AI lab as part of their extended workforce.

What the work involves

• Guide research and engineering teams to close knowledge gaps and improve AI model performance in software engineering, code review, and open-source maintenance topics.
• Design challenging, realistic engineering tasks grounded in the open-source codebase you know best, and write accurate, well-structured reference solutions.
• Evaluate AI-written code, tests, and grading rubrics against the repository's architecture, conventions, and quality bar, and provide clear written technical feedback.
• Build, run, and test the project locally, including with Docker, to confirm that tasks, solutions, and tests behave as intended.
• Write precise rationales explaining what a strong solution looks like and where AI-generated changes fall short.
• Collaborate with other subject matter experts to keep training data consistent and accurate.

Requirements

• Maintainer of a widely used open-source project (named in MAINTAINERS or CODEOWNERS, or 10+ PR reviews in the last 12 months) or core contributor (3+ substantive merged PRs in the last 12 months).
• The repository is 2+ years old, has real users and an active code review culture, and is primarily human-written.
• Years of sustained open-source contributions, verifiable against your own GitHub account.
• Senior-level code review judgment, including the ability to critically assess AI-written code, tests, and edge cases.
• Hands-on ability to build and run the project and its test suite locally, including with Docker.
• Available 40 hours/week during weekdays on an exclusive basis: no other full-time role and no other AI training or evaluation projects, including other Mercor projects, during the engagement.
• Authorized to work in the United States on a W-2 basis.
• Able to complete any necessary background checks and confidentiality agreements before starting, and to work on a company-provided device.
• Strong written communication skills; all rationales and feedback written personally, in your own words.

Pay and schedule

$150/hr, full time, 40 hours per week on weekdays. Cincinnatus LLC is an Equal Employment Opportunity employer.