Lean Engineer, Formal Mathematics (Lean 4, Mathlib) (Remote, Part-time, $90–$110/hr) — Mercor via AI Gig Scout

Through Mercor, a leading AI lab is looking for Lean engineers, formal mathematicians and proof engineers to help its AI models state and prove mathematics correctly, listed at $90–$110/hr. It is a remote, part-time commitment of at least 20 hours per week on weekdays, as a W-2 position with Cincinnatus LLC (or an appropriate international entity) placed with the lab's extended workforce.

Key responsibilities: write correct, idiomatic Lean 4 statements and proofs that compile against current mathlib (algebra, analysis, number theory, combinatorics, logic); formalize natural-language mathematics from competition problems to research-level lemmas; review AI-generated Lean statements and proofs and give clear written feedback; and help define rubrics for proof quality, statement fidelity and mathlib conventions.

Core qualifications: hands-on Lean 4 formal proof experience (mathlib contributions, a formalization project, a Lean library or tool, or autoformalization work); comfort with mathlib and Lean 4 tactics; a strong background in proof-based mathematics, theoretical computer science or logic; and clear written communication. Nice to have: Coq/Rocq, Isabelle, Agda or Haskell, Lean metaprogramming, or AI-for-math work such as LLM provers and benchmarks like miniF2F, ProofNet or PutnamBench.

Details and apply link: https://aigigscout.com/jobs/mercor/lean-engineer-formal-mathematics-lean-4-mathlib-theorem-proving-list-aaabopj-fwgrigai-ilel5s3?utm_source=itjobs&utm_medium=jobboard&utm_campaign=aigigscout_growth

Disclosure: posted by AI Gig Scout, an independent listing site (not Mercor). The apply link may be a referral link.