Lean 4 Proof Engineer — Mathematical Formalization (AI Training)

About The Role
What if your mathematical expertise could directly shape how AI understands and reasons about formal proofs? We're looking for Lean 4 Proof Engineers to translate advanced mathematics into machine-verifiable formalizations — working at the cutting edge of AI research and formal verification. This is a fully remote, flexible contract role for mathematicians who love precision, structural elegance, and the challenge of pushing proof assistants to their limits.
• Organization: Alignerr
• Type: Hourly Contract
•

Location:
Remote
• Commitment: 10–40 hours/week

What You'll Do
• Translate informal mathematical proofs into clean, well-structured Lean 4 formalizations
• Identify gaps, hidden assumptions, and formalizable sub-structures within complex mathematical arguments
• Construct formalizations that test and extend the limits of existing proof assistants
• Collaborate with AI researchers to design and refine formal verification strategies
• Develop readable, reproducible proof scripts aligned with mathematical best practices and Lean idioms
• Provide expert guidance on proof decomposition, lemma selection, and formal model structuring
• Investigate where automated provers break down — and clearly articulate why
• 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
• Have a strong foundation in rigorous proof writing across areas such as algebra, analysis, topology, logic, or discrete math
• Have hands-on experience with Lean (Lean 3 or Lean 4), Coq, Isabelle/HOL, Agda, or comparable systems — Lean strongly preferred
• Genuinely passionate about formal verification, proof assistants, and the future of mechanized mathematics
• Able to take a dense, informal mathematical argument and express it 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 in settings where automated reasoning frequently fails or requires manual scaffolding
• Prior experience with data annotation, quality evaluation, or AI training workflows
• Strong communication skills for explaining formalization decisions, edge cases, and proof strategies Why Join Us
• Work on cutting-edge AI projects alongside leading research labs
• Fully remote and adaptable — work when and where it suits you
• Freelance autonomy with the structure of meaningful, high-impact technical work
• Operate at the frontier of formal verification — tackling problems that automated tools can't yet solve
• Potential for ongoing work and contract extension as new projects launch
• Global collaboration with researchers pushing the boundaries of AI and mathematics

📌 Lean 4 Proof Engineer (Sydney)
🏢 Alignerr
📍 Sydney