Land a Remote Job
Mercor · Remote job

Open Source Maintainer / Core Contributor – Software Engineer

STEP 1 · PRACTICE FIRSTTake a free AI practice interview for this kind of roleGet my practice interview ↓
STEP 2 · APPLYApply on Mercor when you’re readyApply on Mercor →

You apply directly on Mercor's site. Applying is free. Posted Nov 2, 2026.

Get alerts for new jobs onTelegram
STEP 1 · PRACTICE BEFORE YOUR REAL INTERVIEW

Get your free practice interview for this role

Mercor screens applicants online, often with an AI interview. micro1 offers a free, 18-minute AI practice interview with feedback, and we picked the one closest to this role: Data Annotator. It covers:

Instruction FollowingAttention to DetailLogical Reasoning

Here’s your practice interview

Allow your microphone when it asks, find a quiet spot, and give yourself about 20 minutes. We’ve also emailed you the link and the free ebook.

Step 2: when you feel ready, apply.

Apply on Mercor →

The practice interview is free and run by micro1. Land Remote Jobs is an independent job board, not part of micro1, Mercor or Turing. Practising helps you prepare; it can’t guarantee the result of your real interview. Want more tips? Read our guide to acing the remote job interview.

STEP 2 · APPLY

Apply for this role

You apply on Mercor's own site. It’s free, and you can apply even if you skip the practice.

Apply on Mercor →

Who this role suits

Working engineers who want flexible, project-based remote work that uses their coding and review skills. A strong portfolio or GitHub helps.

Full job description

Join a leading AI lab's cutting-edge GenAI team to be at the core of the AI revolution, where your expertise fuels the development of the most advanced Large Language Models.

1. Overview

Join a leading AI lab's cutting-edge GenAI team and help build foundational AI models from the ground up. We're seeking talented open-source maintainers and core contributors with deep, hands-on ownership of a mature, widely used open-source codebase to bring real-world engineering and code review judgment and elevate the quality of our AI training data. This is a full-time commitment of 40 hours per week.

This is a W-2 employment position with Cincinnatus LLC, with the opportunity to be placed at a leading AI Lab as part of their extended workforce.

2. Key Responsibilities

  • 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 the expert knows best, such as the features, refactors and bug fixes a maintainer would assign, 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 that explain what a strong solution looks like and where AI-generated changes fall short.

  • Collaborate with other subject matter experts to ensure consistency and accuracy in training data.

3. Core Qualifications

  • Maintainer (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) of a widely used open-source project.

  • 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, with a public history that can be verified against the candidate's 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.

  • Ability to engage reliably for 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 to protect the security of information.

  • Writes all rationales and feedback personally, in their own words.

  • Strong written communication skills and the ability to explain complex technical decisions clearly.

About Cincinnatus LLC: Cincinnatus LLC is an enterprise staffing company that partners with leading technology companies to source and employ highly skilled professionals for contingent and contract-based opportunities. Cincinnatus serves as the employer of record for these engagements, providing W-2 employment, payroll, benefits, and compliance, while placing employees directly within client teams to work on high-impact initiatives.

Equal Employment Opportunity: Cincinnatus is proud to be an Equal Employment Opportunity employer. We do not discriminate based upon race, religion, color, national origin, sex (including pregnancy, childbirth, reproductive health decisions, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, genetic information, political views or activity, or any other legally protected characteristic.

Last checked open on Nov 3, 2026. Job description provided by Mercor.

Something not working? Tell us

If the practice interview or the apply link doesn’t open, or the job looks closed, let us know and we’ll fix it.

← Browse all remote jobs