Lean 4 Proof Engineer - Mathematical Formalization

About the Role

What if your deep mathematical expertise could directly shape the future of AI reasoning? We're looking for Lean 4 Proof Engineers to formalize advanced mathematical arguments into machine-verifiable proofs — working at the very frontier of what modern proof assistants can express, capture, and automate.

This is a fully remote, flexible contract role built for mathematicians who live at the intersection of rigorous proof construction and formal verification. If you find genuine satisfaction in taking a dense, elegant human argument and expressing it in a form a machine can understand, this role was designed for you.

What You'll Do

• Translate informal mathematical proofs into Lean 4 (and related proof systems) with emphasis on clarity, structure, and correctness
• Analyze generic and domain-specific proofs — identifying 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 strategies for improving formal verification pipelines
• Create highly readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms
• Provide expert guidance on proof decomposition, lemma selection, and structuring techniques 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 reveal 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 formal systems — with Lean strongly preferred
• Deeply enthusiastic about formal verification, proof assistants, and the future of mechanized mathematics
• Able to translate informal mathematical arguments into clean, structured, and machine-checkable formalizations
• Comfortable working independently with precision and intellectual rigor

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, data quality, or AI evaluation systems
• Strong communication skills for explaining formalization decisions, edge cases, and reasoning strategies

Why Join Us

• Work on cutting-edge AI projects alongside world-leading research labs
• Fully remote and flexible — work when and where it suits you
• Freelance autonomy with the structure of meaningful, intellectually stimulating work
• Get direct exposure to how advanced AI models are trained and evaluated on mathematical reasoning
• Contribute to mapping the frontier of what formal verification can achieve
• Potential for ongoing work and contract extension as new projects launch

Organization

Organization: Alignerr

Type

Type: Hourly Contract

Location

Location: Remote

Commitment

Commitment: 10–40 hours/week