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Lean 4 Proof Engineer - Mathematical Formalization

$170-200/hrRemoteFreelanceSTEM

About the Role

What if your deep mathematical expertise could directly influence how the world's most advanced AI systems reason, prove, and think? We're looking for Lean 4 Proof Engineers to translate rigorous human mathematics into machine-verifiable formalizations — working at the precise frontier where formal verification meets cutting-edge AI research.

This is a fully remote, flexible contract role built for mathematicians who find beauty in precision and satisfaction in expressing dense, elegant arguments in a form a machine can verify and learn from.

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

What You'll Do

  • Translate informal mathematical proofs into Lean 4 — emphasizing clarity, correctness, and structural elegance
  • Analyze proofs across domains, identifying hidden assumptions, logical gaps, and formalizable substructures
  • Construct formalizations that push proof assistants to their limits — especially where automated tools struggle or fail entirely
  • Collaborate with AI researchers to design and refine formal verification strategies and pipelines
  • Develop highly readable, reproducible proof scripts aligned with mathematical best practices and Lean idioms
  • Provide expert guidance on proof decomposition, lemma selection, and structuring techniques for formal models
  • Formalize classical and advanced proofs, then compare machine-verifiable structures against textbook arguments
  • Articulate precisely where and why automated provers break down — and help map a path forward

Who You Are

  • Advanced degree (Master's or PhD) in Mathematics, Logic, Theoretical Computer Science, or a closely related field
  • Strong foundation in rigorous proof construction across areas such as algebra, analysis, topology, logic, or discrete mathematics
  • Hands-on experience with Lean (Lean 3 or Lean 4) — Lean 4 strongly preferred
  • Experience with formal proof systems such as Coq, Isabelle/HOL, or Agda is a strong plus
  • Deeply enthusiastic about formal verification, proof assistants, and mechanized mathematics
  • Able to translate informal arguments into clean, structured, machine-verifiable proofs
  • Self-directed and comfortable working independently on complex, open-ended problems

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 genuinely frontier problems — proofs that exceed the current capabilities of automated systems
  • Collaborate with leading AI research labs on cutting-edge model training
  • Gain direct exposure to how advanced LLMs are trained to reason mathematically
  • Fully remote and asynchronous — work when and where it suits you
  • Freelance autonomy with meaningful, intellectually stimulating work
  • Potential for ongoing contract extension as new research projects launch