Applied Formal Methods Engineer

Formel AI offers a founding role at the intersection of AI and formal methods. Join us in building trustworthy LLMs that never hallucinate and cost less to run.

About The Role

We are looking for an engineer with a strong background in formal methods who will help us bridge AI and formal verification, building production‑grade systems and translating research into practical implementations.

Key Responsibilities

• Develop product features: Build and ship production‑grade features for our platform, working from backend APIs to UI prototypes using Python.
• Bridge theory and practice: Translate cutting‑edge research in formal methods and AI into production‑grade systems, acting as a reference on complex technical concepts in the team.
• Stay at the forefront of AI and formal methods: Monitor research in both fields, identify emerging techniques and tools that could enhance our systems.
• Drive research innovation: Actively shape the company’s research roadmap, exploring new leads in applied formal verification in collaboration with our scientific advisory board.

What we are looking for

Essential Qualities

• Curious and scientific: Passion for exploring the intersection of AI and formal methods, with a research‑driven mindset that constantly questions and pushes boundaries.
• High technical skills: Autonomously design, implement, and deploy production‑grade systems that integrate formal verification with AI, from prototyping to production.
• High theoretical skills in formal methods: Deep expertise in formal verification, theorem proving, and SMT solving, with the ability to apply these concepts to real‑world problems.
• Impact driven: Translate cutting‑edge research into practical implementations that deliver measurable value, always keeping real‑world applicability at the forefront.
• Bridge builder: Build interdisciplinary bridges and thrive in collaborative environments.

Background

• Advanced degree in formal methods or related field: PhD or Master’s degree in Computer Science, Mathematics, or a related discipline with a focus on formal verification, theorem proving, or program analysis.
• 3+ years of experience: Substantial professional or research experience applying formal methods to complex systems.
• Industry or academic research: Experience in either industrial R&D labs or academic research groups working on formal verification tools and techniques.
• Track record of end‑to‑end product development: Proven experience taking formal methods projects from research concept through implementation to production deployment.

Required Skills

• Applied formal methods expertise: Demonstrated track record of applying formal verification techniques to real‑world problems.
• Theorem proving experience: Hands‑on experience with at least one interactive theorem prover (e.g., Rocq, Isabelle/HOL, Lean, or similar).
• SMT solver knowledge: Strong understanding of SMT solver fundamentals and their practical applications.
• Team‑based product development: Experience collaborating in a team environment to build and ship production software.
• Formal software development: Proven experience developing formally verified software or integrating formal methods into software development workflows.

Nice‑to‑have

• Python proficiency: Strong programming skills in Python for rapid prototyping and integration.
• OCaml experience: Familiarity with OCaml or other functional programming languages.
• LLMs knowledge: Understanding of LLMs from both theoretical and practical perspectives.

Benefits

• Financial & perks
• Competitive cash salary and equity (BSPCE) in a high‑potential company.
• Health insurance (Alan) for you and your family (partner and kids).
• Daily lunch vouchers (Swile).
• Hybrid work model with a strong emphasis on in‑office collaboration (typically 3‑4 days per week at the office) to foster team cohesion, spontaneous discussions, and deep work together.
• What makes this role unique:
  • Founding team impact: Join as one of the first employees and shape the trajectory of a moonshot deep‑tech company.
  • Mission‑driven startup: Help solve the key pressing challenges of AI—ensuring LLMs are trustworthy, transparent, and cost‑effective, with direct benefits for environmental sustainability.
  • Work with cutting‑edge technology: Build systems that combine LLMs with formal verification—an emerging field at the forefront of AI safety and reliability where breakthrough developments happen every week.
  • World‑class team: Collaborate with a scientific advisory board from leading institutions (Ecole Polytechnique, ENS Paris‑Saclay, etc) and experienced business angels from top tech companies (Datadog, Dataiku, Nabla, Artefact, and more).
  • Strategic customers: Work with leading companies in healthcare, enterprise software, and other mission‑critical domains.
  • Flexibility of an early‑stage startup: Autonomy to define how you work and what you prioritize.

Hiring Process

• Apply and submit your resume using this Google Form:
• Screening call (30 min): A quick chat with the CTO to align on vision and expectations.
• In‑depth technical discussion (home exercise followed by a 60 min discussion): Best way to decide if we are a great fit as potential collaborators.
• Technical deep‑dive (60 min): A focus on your proficiency with the tools you will use.
• Founder interview (45 min): Final discussion on strategy, culture fit, and your long‑term evolution within the company, with the CTO and CEO.

Location: 75000 Paris, France