All AI training jobs

Mercor · STEM & research

Formal Mathematics Specialist (Lean / Coq / Isabelle) - review AI outputs in your specialty

Listed on Mercor as “Formal Mathematics Specialist (Lean / Coq / Isabelle)”

$80-$130/hrRemoteContractPaid in USD
ShareWhatsAppTelegramEmail

How this rate compares

This listing

$80–$130 per hour

Typical in STEM & research

$70–$120 per hour

Within the typical range

Typical: the middle of the lowest and highest rates posted by 52 listings in this category on Seoulstart, in US dollars.

What this actually is

You design problems that stump current AI models, evaluate AI reasoning against the correct answer, write rubrics, and provide expert feedback. Often the highest-paid category because the expertise pool is small. The platform title (Formal Mathematics Specialist (Lean / Coq / Isabelle)) reflects the rate band and the expertise required, not the day-to-day work.

How Mercor picks people

  1. Upload your CV and answer the role's written questions.
  2. Do a video interview with Mercor's AI interviewer. Most take about 20 minutes, in English unless the role says otherwise.
  3. Some roles add a skills test. A test you pass once counts for similar roles.
  4. The project team reviews your results and sends offers to the people it picks.

Before you start

  • Take Mercor's free practice interview first. It does not count toward any application.
  • Use Chrome on a computer with a camera and microphone, in a quiet room.
  • You can retake an official interview up to 3 times, but hiring teams see how many times you retook it.

Not every applicant gets an offer. Prepare well for the interview.

How to prepare for the Mercor interview

Source: Mercor's help pages. talent.docs.mercor.com

Can you do this on your visa?

F-2 / F-4 / F-5 / F-6: open. E-1 to E-7: needs concurrent-employment permit. D-2 / D-4 students: S-3 permit, 20 hr/week cap. D-10 / D-8: case by case.

Korean tax on USD income

First 5 years in Korea: foreign-source income only taxed if remitted into Korea. After year 5: worldwide income. Full tax guide.

Original posting from Mercor

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 Formal Mathematics specialists and mathematicians with hands-on experience with interactive theorem provers such as Lean, Coq (Rocq) or Isabelle to bring rigorous mathematical and formal verification expertise and elevate the quality of our AI training data.

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 formal mathematics and theorem proving, formalized proofs, and graduate-level mathematics topics.
  • Design challenging, domain-relevant tasks, and write accurate and well-structured solutions to formal mathematics and theorem proving problems.
  • Evaluate formal mathematics and theorem proving tasks and solutions and provide clear, written technical feedback.
  • Write, check and repair formal proofs and statements in Lean, Coq or Isabelle, and translate informal mathematics into formal statements.
  • Develop rubrics to assess the correctness, faithfulness and elegance of formalized statements and proofs.
  • Collaborate with other subject matter experts to ensure consistency and accuracy in training data.

3\. Core Qualifications

  • Graduate-level training in mathematics, computer science or logic (MS, PhD or PhD candidate), or equivalent professional experience in formal verification.
  • Hands-on experience writing proofs in Lean 4 (Mathlib), Coq (Rocq), Isabelle/HOL or a comparable proof assistant, evidenced by contributions, projects or publications.
  • Strong background in proof-based mathematics (algebra, analysis, number theory, combinatorics or logic).
  • Demonstrable track record of mathematical or formal verification work.
  • Ability to engage reliably for at least 20 hours/week during weekdays.
  • 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.

Quoted from Mercor's public listing on 2026-11-13. We don't edit platform copy; honest framing is in the title and the “what this actually is” block above.

Mercor pays Seoulstart a fee if it hires you through this link. Your pay is the same.