Lean 4 Proof Engineer - Mathematical Formalization

Alignerr partners with leading AI research teams to build and train advanced AI models. They are seeking a Lean 4 Proof Engineer who will formalize advanced mathematical proofs for AI research, focusing on translating human-written arguments into machine-verifiable formalizations.

Responsibilities:

• Translate informal mathematical proofs into Lean (and related proof systems) with an 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 tools struggle or fail
• Collaborate with researchers to design, refine, and evaluate strategies for improving formal verification pipelines
• Develop highly readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms
• Provide 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 why (complexity, missing lemmas, insufficient libraries, etc.)
• Create Lean proofs that reveal deeper patterns or generalizations implicit in the original mathematics

Requirements:

• Master's degree (or higher) in Mathematics, Logic, Theoretical Computer Science, or a closely related field
• Strong foundation in rigorous proof writing and mathematical reasoning across areas such as algebra, analysis, topology, logic, or discrete math
• Hands-on experience with Lean (Lean 3 or Lean 4), Coq, Isabelle/HOL, Agda, or comparable systems, with Lean strongly preferred
• Deep enthusiasm for formal verification, proof assistants, and the future of mechanized mathematics
• Ability to translate informal arguments into clean, structured formal proofs
• Prior experience with data annotation, data quality, or evaluation systems
• Familiarity with type theory, Curry-Howard correspondence, and proof automation tools
• Experience with large-scale formalization projects (e.g., mathlib)
• Exposure to theorem provers where automated reasoning frequently fails or requires manual scaffolding
• Strong communication skills for explaining formalization decisions, edge cases, and reasoning strategies