Lean 4 Proof Engineer — Mathematical Formalization About The Role What if your mathematical expertise could directly shape the future of AI reasoning? We're looking for Lean 4 Proof Engineers to translate advanced human-written mathematics into precise, machine-verifiable formalizations — working at the cutting edge of what proof assistants can express, capture, and automate. This is a fully remote, flexible contract role built for mathematicians who love rigorous proof construction and want their work to matter beyond the page.

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 systems) with a focus on clarity, correctness, and structure

Analyze domain-specific and general proofs to identify 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 formal verification strategies

Develop readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms

Provide expert guidance on proof decomposition, lemma selection, and structuring techniques

Investigate where automated provers break down and articulate the underlying reasons — complexity, missing lemmas, insufficient libraries, and beyond

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

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 systems — Lean strongly preferred

Deeply enthusiastic about formal verification, proof assistants, and the future of mechanized mathematics

Able to translate dense informal arguments into clean, precisely structured formal proofs A mathematically mature problem-solver who finds satisfaction in expressing an elegant human argument 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 where automated reasoning frequently fails or requires manual scaffolding

Prior experience with data annotation, evaluation systems, or data quality workflows

Strong communication skills for explaining formalization decisions, edge cases, and proof strategies Why Join Us Work at the frontier of AI research alongside world-leading research labs and teams

Fully remote and versátil — structure your work around your life, not the other way around

Freelance autonomy with intellectually meaningful, high-impact work

Direct exposure to how cutting-edge large language models are trained and evaluated

Contribute to work that is genuinely pushing the boundaries of what machines can understand and verify

Potential for ongoing contract extension as new projects launch

📌 Lean 4 Proof Engineer - Mathematical Formalization (Ciudad de México)
🏢 Alignerr
📍 Ciudad de México