Lean 4 Proof Engineer - Mathematical Formalization

Lean 4 Proof Engineer — Mathematical Formalization

About the Role

What if your mathematical expertise could directly shape the future of AI reasoning? We're looking for Lean 4 Proof Engineers to translate advanced human-written mathematics into precise, machine-verifiable formalizations — working at the cutting edge of what proof assistants can express, capture, and automate.

This is a fully remote, flexible contract role built for mathematicians who love rigorous proof construction and want their work to matter beyond the page.

• 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 systems) with a focus on clarity, correctness, and structure
• Analyze domain-specific and general proofs to identify gaps, hidden assumptions, and formalizable sub-structures
• Construct formalizations that test the limits of existing proof assistants — especially where automated tools struggle or fail
• Collaborate with AI researchers to design, refine, and evaluate formal verification strategies
• Develop readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms
• Provide expert guidance on proof decomposition, lemma selection, and structuring techniques
• Investigate where automated provers break down and articulate the underlying reasons — complexity, missing lemmas, insufficient libraries, and beyond
• Create Lean proofs that surface deeper patterns or generalizations implicit in the original mathematics

Who You Are

• Hold a Master's degree or higher in Mathematics, Logic, Theoretical Computer Science, or a closely related field
• Possess a strong foundation in rigorous proof writing across areas such as algebra, analysis, topology, logic, or discrete mathematics
• Have hands-on experience with Lean (Lean 3 or Lean 4), Coq, Isabelle/HOL, Agda, or comparable systems — Lean strongly preferred
• Deeply enthusiastic about formal verification, proof assistants, and the future of mechanized mathematics
• Able to translate dense informal arguments into clean, precisely structured formal proofs
• A mathematically mature problem-solver who finds satisfaction in expressing an elegant human argument in a form a machine can verify

Nice to Have

• Familiarity with type theory, the Curry-Howard correspondence, and proof automation tools
• Experience contributing to large-scale formalization projects such as Mathlib
• Exposure to theorem provers where automated reasoning frequently fails or requires manual scaffolding
• Prior experience with data annotation, evaluation systems, or data quality workflows
• Strong communication skills for explaining formalization decisions, edge cases, and proof strategies

Why Join Us

• Work at the frontier of AI research alongside world-leading research labs and teams
• Fully remote and flexible — structure your work around your life, not the other way around
• Freelance autonomy with intellectually meaningful, high-impact work
• Direct exposure to how cutting-edge large language models are trained and evaluated
• Contribute to work that is genuinely pushing the boundaries of what machines can understand and verify
• Potential for ongoing contract extension as new projects launch