Lean 4 Proof Engineer - Mathematical Formalization
About this role
About the Role What if your deep mathematical training could directly shape the future of AI reasoning? We're looking for Lean 4 Proof Engineers to formalize advanced mathematical proofs for cutting-edge AI research — working at the precise intersection where rigorous mathematics meets machine-verifiable logic. This is a fully remote, flexible contract role built for mathematicians who find genuine satisfaction in translating elegant human arguments into structures a machine can understand and verify. If you live for precision and thrive at the frontier of what formal proof assistants can do, this role was made for you. - Organization: Alignerr - Type: Hourly Contract - Location: Remote - Commitment: 10–40 hours/week What You'll Do - Translate informal mathematical proofs into Lean 4 (and related proof systems) with a focus on clarity, structure, and correctness - Analyze generic and domain-specific proofs — identifying gaps, hidden assumptions, and formalizable sub-structures - Construct formalizations that push the limits of existing proof assistants, especially where tools struggle or fail - Collaborate with AI researchers to design, refine, and evaluate strategies for improving formal verification pipelines - Develop highly readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms - Guide proof decomposition, lemma selection, and structuring strategies for formal models - Formalize classical proofs and compare machine-verifiable structures against textbook arguments - Investigate where automated provers break down — and articulate precisely why (complexity, missing lemmas, insufficient libraries, etc.) - Create Lean proofs that surface deeper patterns or generalizations implicit in the original mathematics Who You Are - Master's degree or higher in Mathematics, Logic, Theoretical Computer Science, or a closely related field - Strong foundation in rigorous proof writing across areas such as algebra, analysis, topology, logic, or discrete mathematics - Hands-on experience with Lean (Lean 3 or Lean 4), Coq, Isabelle/HOL, Agda, or comparable systems — Lean strongly preferred - Deep enthusiasm for formal verification, proof assistants, and the future of mechanized mathematics - Ability to translate informal mathematical arguments into clean, well-structured formal proofs - Self-motivated and capable of working independently in an asynchronous, remote environment Nice to Have - Familiarity with type theory, the Curry-Howard correspondence, and proof automation tools - Experience contributing to large-scale formalization projects (e.g., Mathlib) - Exposure to theorem provers where automated reasoning frequently fails or requires manual scaffolding - Prior experience with data annotation, data quality, or evaluation systems - Strong communication skills for explaining formalization decisions, edge cases, and reasoning strategies Why Join Us - Work directly on cutting-edge AI projects alongside world-leading research labs - Fully remote and async-friendly — work when and where it suits you - Freelance autonomy with the structure of meaningful, intellectually stimulating work - Contribute to mapping the frontier of what formal verification can express, capture, and automate - Gain rare exposure to how advanced AI models are trained and evaluated at the highest level - Potential for ongoing work and contract extension as new projects launch
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