Mercor
Lean Engineer, Formal Mathematics (Lean 4, Mathlib, Theorem Proving)
- Pay
- $90–110/hr
- Type
- Part-time
- Location
- Remote
- Posted
- Sep 30, 2026
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About this role
Help a leading AI lab teach its models to write real, machine-checked mathematics in Lean. 1\. Overview A leading AI lab is looking for Lean engineers, formal mathematicians and proof engineers to help its AI models state and prove mathematics correctly. You'll write and review Lean 4 proofs, turn informal math into precise formal statements, and help the lab's researchers judge whether a model's proof is not just accepted by the checker but actually proves the right thing. If you enjoy writing Lean, know your way around mathlib, and can explain why a formalization is faithful or subtly wrong, this role is for you. This is a part-time commitment of at least 20 hours per week, with the option to increase to up to 40 hours per week. This is a W-2 employment position with Cincinnatus LLC (or appropriate international entity), with the opportunity to be placed at a leading AI lab as part of…
