Lean 4 Proof Engineer - Mathematical Formalization

Lean 4 Proof Engineer — Mathematical Formalization

About the Role

What if your deep mathematical training could directly shape how AI understands and reasons about formal proof? We're looking for Lean 4 Proof Engineers to formalize advanced mathematics for cutting-edge AI research — translating rigorous human arguments into precise, machine-verifiable proofs that push the limits of what automated systems can express and verify.

This is a fully remote, flexible contract role designed for mathematicians who find genuine satisfaction in the intersection of formal logic, proof theory, and modern proof assistants.

• Organization: Alignerr
• Type: Hourly Contract
• Location: Remote
• Commitment: 10–40 hours/week

What You'll Do

• Translate informal mathematical proofs into clean, structured Lean 4 formalizations with an emphasis on clarity, correctness, and reproducibility
• Analyze proofs across domains — identifying hidden assumptions, gaps, and formalizable sub-structures
• Construct formalizations that test and extend the limits of existing proof assistants, especially where automation breaks down
• Collaborate with AI researchers to design and refine formal verification pipelines
• Investigate failure modes of automated provers and articulate root causes — missing lemmas, library gaps, complexity barriers
• Provide expert guidance on proof decomposition, lemma selection, and structuring strategies for formal models
• Create Lean proofs that reveal 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 algebra, analysis, topology, logic, or discrete mathematics
• Hands-on experience with Lean (Lean 3 or Lean 4), Coq, Isabelle/HOL, Agda, or comparable formal systems — Lean 4 strongly preferred
• Deep enthusiasm for formal verification, proof assistants, and mechanized mathematics
• Able to take dense, human-written arguments and express them precisely in machine-verifiable form
• A methodical problem-solver who thrives at the frontier — where the tools aren't enough and judgment matters

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 in regimes where automated reasoning frequently fails or requires manual scaffolding
• Prior experience with data annotation, evaluation systems, or AI training workflows
• Strong written communication skills for documenting formalization decisions, edge cases, and reasoning strategies

Why Join Us

• Work at the frontier of formal mathematics and AI research alongside world-leading research labs
• Fully remote and flexible — work when and where it suits you
• Freelance autonomy with meaningful, intellectually stimulating project-based work
• Contribute to a field that is actively shaping the future of AI reasoning and mathematical automation
• Potential for contract extension as new projects launch