AlignerrCoding & software eval
Lean 4 Proof Engineer - Mathematical Formalization
up to $200/hr
About this role, in Alignerr's words
What if your deep mathematical expertise could directly shape how AI reasons, proves, and understands the foundations of mathematics? We're looking for Lean 4 Proof Engineers to translate rigorous human-written arguments into machine-verifiable formalizations — working at the very frontier of what proof assistants can express and automate.
What you'll do
- Translate informal mathematical proofs into Lean 4 (and related proof systems) with an emphasis on clarity, structure, and correctness
- Analyze both generic and domain-specific proofs — identifying gaps, hidden assumptions, and formalizable sub-structures
- Push the limits of existing proof assistants by constructing formalizations where tools struggle or fail
Show all 9 itemsHide the other 6 in What you'll do
- Collaborate with AI researchers to design, refine, and evaluate formal verification strategies
- Develop highly readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms
- Provide expert guidance on proof decomposition, lemma selection, and structuring techniques
- Formalize classical proofs and compare machine-verifiable structures against textbook arguments
- Articulate and document where and why automated provers break down — complexity, missing lemmas, insufficient libraries, and more
- Surface deeper patterns or generalizations implicit in the original mathematics through your Lean formalizations
Candidate background
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 informal arguments into clean, well-structured formal proofs
- A mathematically mature problem-solver who finds satisfaction in taking a dense, elegant argument and expressing it in a form a machine can verify
Nice to Have
Show all 5 itemsHide these 5 items in Nice to Have
- Familiarity with type theory, the Curry-Howard correspondence, and proof automation tools
- Experience with 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 written communication skills for documenting formalization decisions, edge cases, and reasoning strategies
Quoted from selected sections of Alignerr's posting. The full posting may state other conditions. Read the full posting
A closer look
More context, when you need it.
Full job descriptionThe original posting, in Alignerr's words
Posted by Alignerr, reproduced here so you can judge the role before clicking. Original posting ↗
Lean 4 Proof Engineer — Mathematical Formalization (AI Training)
About the Role
What if your deep mathematical expertise could directly shape how AI reasons, proves, and understands the foundations of mathematics? We're looking for Lean 4 Proof Engineers to translate rigorous human-written arguments into machine-verifiable formalizations — working at the very frontier of what proof assistants can express and automate.
This is a fully remote, flexible contract role for mathematicians who love precision, structural elegance, and the challenge of making formal verification go further than it's ever gone before.
- 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 an emphasis on clarity, structure, and correctness * Analyze both generic and domain-specific proofs — identifying gaps, hidden assumptions, and formalizable sub-structures * Push the limits of existing proof assistants by constructing formalizations where tools struggle or fail * Collaborate with AI researchers to design, refine, and evaluate formal verification strategies * Develop highly readable, reproducible proof scripts aligned with mathematical best practices and proof assistant idioms * Provide expert guidance on proof decomposition, lemma selection, and structuring techniques * Formalize classical proofs and compare machine-verifiable structures against textbook arguments * Articulate and document where and why automated provers break down — complexity, missing lemmas, insufficient libraries, and more * Surface deeper patterns or generalizations implicit in the original mathematics through your Lean formalizations
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 informal arguments into clean, well-structured formal proofs * A mathematically mature problem-solver who finds satisfaction in taking a dense, elegant argument and expressing it in a form a machine can verify
Nice to Have
* Familiarity with type theory, the Curry-Howard correspondence, and proof automation tools * Experience with 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 written communication skills for documenting formalization decisions, edge cases, and reasoning strategies
Why Join Us
* Work on frontier AI projects alongside leading research labs and teams * Fully remote and flexible — structure your work around your schedule * Freelance autonomy with intellectually stimulating, high-impact work * Gain rare exposure to how advanced AI models are trained on formal mathematical reasoning * Contribute to expanding the boundary of what machines can formally understand and verify * Potential for ongoing work and contract extension as new projects launch
Working with AlignerrPay, getting started and work, from Alignerr's own pages
What the platform publishes in general. These are not extra terms confirmed for this particular role.
- Getting paid
- Billed weekly, Monday to Sunday, with approved work paid by the following Friday, according to Labelbox's help center. Payment goes through Stripe Connect or PayPal depending on your location, with one provider per country. intercom.help/labelbox/en/articles/13600616-alignerr-paym..., alignerr.com/process
- Before your first paid task
- Sign up, apply, verify your identity, set up billing and onboard. Some jobs add a Zara AI interview or domain assessments. alignerr.com/process
- How much work
- Time to your first project depends on demand and your skills, and there is no minimum number of hours. alignerr.com/faqs
- Contract
- Independent contractor, under terms with ALIGNERR LLC. alignerr.com/faqs, alignerr.com/privacy
Read on the pages linked above on 24 Sep 2026. Platforms change these terms, so check the linked page before you rely on one.
How does the pay compare?Across Coding & software eval roles, not this role alone
From our own daily reads of every open listing on the platforms we follow, not from Alignerr's posting. How we count.
Pay across the field: Coding & software eval
Across 393 roles in this field with a stated hourly rate in US dollars, on 14 platforms, the middle half pays $65 to $120 an hour at the top of the range, and the median is $95. This role's top rate, $200, is in the top quarter. Of the 140 distinct rates we count, 133 are lower and 4 are higher.
| Platform | Roles | Top of range, per hour |
|---|---|---|
| Alignerr (this platform) | 136 | $50 to $400 · median $100 |
| micro1 | 46 | $35 to $350 · median $110 |
| Handshake AI | 43 | $47 to $125 · median $80 |
| Meridial (Invisible) | 34 | $22 to $150 · median $60 |
| Mercor | 33 | $60 to $200 · median $105 |
Sources and listing historyWhere this information comes from
This listing's history
- First seen here on 27 Aug 2026, and still on Alignerr's list when we last read it on 13 Oct 2026.
- The listed pay has not changed since then.
- Posted by Alignerr
- First seen by AIPayList
- Last seen live
- Listing ID
- 0106950d-7d32-4495-9f0c-1f05a617173a
Pay as the source states it: “$170-200/hr”.
Platforms sometimes change a rate after posting. Every listing here is re-read at least once a day and corrected when its source moves, so a difference you see on the platform is usually a change made since the last read. How freshness works.
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