Lean 4 Proof Engineer - Mathematical Formalization

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
• Create 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