Mathematics Expert

We are looking for mathematicians to help train and evaluate AI models on advanced mathematical reasoning. You will write problems with complete solutions, verify model reasoning step by step, and classify the errors that models make.

Key Responsibilities

• Write proof-based and computational problems with complete, rigorous solutions.
• Verify AI-generated solutions step by step and identify logical gaps, unjustified steps and calculation errors.
• Classify error types so the project team can see where models fail.
• Write grading rubrics and reference solutions at a consistent level of difficulty.
• Review problems written by other experts for correctness, clarity and originality.
• Provide clear written explanations suitable for model training.
• Follow project guidelines, take part in calibration and review sessions, and incorporate feedback to keep quality consistent.

Required Qualifications

• Master's or PhD in mathematics, or a Bachelor's plus 2+ years of relevant experience.
• Strong command of at least one core area (analysis, algebra, number theory, probability, combinatorics or geometry).
• Ability to write clear, rigorous proofs.
• Excellent written English.
• Reliable, detail-oriented, and able to work independently and meet deadlines in a remote setting.

Preferred Qualifications

• Research or mathematical competition experience.
• Experience with symbolic or numerical tools (Python, Mathematica, Lean).
• Teaching or problem-writing experience.

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.