Join Jus Mundi – To Power Global Justice 🚀⚖️

Founded in 2019 and recognized as a mission-led company, Jus Mundi is pioneering legal technology to power global justice through artificial intelligence. 🌍

Headquartered in Paris, with additional offices in New York, London, and Singapore, Jus Mundi serves over 150,000 users, including top law firms, multinational corporations, government bodies, and academic institutions in more than 90 countries. By combining legal expertise with cutting-edge AI technology, we provide global legal intelligence, data-driven arbitration professional selection, and business development services.

What Makes Jus Mundi the Place to Be 🌟

• 🧬 Our Values: With core values as Friendly, Committed, Explorative, and Excelsior, we cultivate a dynamic environment that encourages collaboration, innovation, and continuous growth.
• 🚀 Legal Is the Next Frontier for GenAI: Legal is one of the top industries ready to be transformed by GenAI. At Jus Mundi, we’re building transformative AI where it has the power to make the most impact.
• 🌐 Proven Product Market Fit: Jus Mundi has secured product-market fit in global markets since launch, partnering with top-tier law firms, government bodies, and major corporations, including: Freshfields, Quinn Emanuel, Wong Partnership, Total Energies, Canada, UK, and Japan.
• 💸 Strategic Investment: We recently raised over $20 million in Series B funding from prominent strategic international investors, including Acton Capital, True Global Ventures, C4 Ventures, and FJ Labs, fueling our growth and innovation.
• 🤖 Legal Meets Tech: Our engineers and former lawyers collaborate closely with large language models (LLMs) to pioneer the future of generative AI and reshape professional services.
• 🌟 Exceptional Team: Work with talented professionals from industry leaders, including engineers, legal experts, and AI specialists from companies like Google and Amazon who are pushing the boundaries of legal tech.

📌 About the Role

Jus Mundi is building the AI layer for international law and arbitration — turning a vast, multilingual corpus of case law, treaties, and legal analysis into answers practitioners can trust.

We are looking for a Senior AI engineer to own the applied AI systems behind that: search relevance and retrieval, RAG over legal documents, autonomous research agents, and the evaluation harnesses that keep them accurate. This is a hands-on senior role with scope beyond a single squad.

You will take ambiguous problems — "make our search more relevant," "let users ask a question and get a cited answer" — and turn them into concrete technical roadmaps, then ship them to production with measurable impact. The differentiators for this role are deep expertise in building autonomous agents (orchestration loops, tool calling, and memory — not just retrieval-augmented systems), a critical command of evaluation and benchmarking, and hands-on fine-tuning and synthetic-data generation. You will set patterns other engineers build on, and raise the bar through mentoring, reviews, and hiring.

AI depth is the core of the role; you should be comfortable integrating your work into our stack, but this is not a general full-stack position.

🌟Your mission at Jus Mundi

• Search & Retrieval Relevance: Own and improve retrieval and ranking over a large, multilingual legal corpus — a problem where relevance directly drives product value. Design, measure, and iterate on RAG pipelines that ground answers in the right sources.
• Agent Orchestration (core of this role): Design and build agentic systems from the ground up — orchestration loops, tool/function calling, short- and long-term memory, state management, planning, and multi-step reasoning over documents. This goes well beyond wiring up a RAG pipeline: we need someone who has architected the control loop itself and made it reliable enough for a professional audience.
• Evaluation & Benchmarking (core of this role): Design and run rigorous evals and benchmarks with a critical understanding of the methods themselves — knowing which metric measures what, where LLM-as-a-judge is trustworthy and where it isn't, and how to build regression suites and benchmark tracking that catch model degradation. Hold the bar on hallucinations and citation accuracy, which is non-negotiable in a legal setting.
• Fine-Tuning & Synthetic Data: Fine-tune open-source or proprietary models (e.g. LoRA/QLoRA) when it beats prompting or retrieval, and generate high-quality synthetic data to train and evaluate them. Curate domain datasets and make explicit trade-offs — precision vs. recall, cost vs. quality — rather than defaulting to the "perfect" academic solution.
• Production & LLMOps: Deploy AI features to production and own their latency, cost, and reliability. Design systems that degrade gracefully under load or model failure instead of breaking catastrophically.
• Leverage Across Squads: Build the shared tooling, libraries, and patterns (eval infra, retrieval components, agent scaffolding) that speed up other squads, not just your own — and pay down systemic AI/data debt before it stalls the team.
• Technical Leadership: Act as the go-to resource for complex modeling and GenAI problems. Level up engineers through code review and RFCs, and contribute to hiring — interviews, bar-raising, and onboarding.

⚙️ Preferred Experience and Skills

• Applied AI Depth: Proven track record shipping LLM-powered features to production — API integration (OpenAI, Anthropic, Mistral) and open-source models (Hugging Face) — with clear, measurable impact.
• Retrieval & RAG: Strong command of vector databases, retrieval and ranking, and RAG architecture, including how to actually improve relevance and evaluate it.
• Agentic Systems (critical requirement): Deep, hands-on expertise designing and building agent orchestration loops — tool/function calling, memory, planning, error recovery, and state management. You must be able to point to something you have actually built and shipped in this space (custom architectures or frameworks like LangGraph, LangChain, LlamaIndex, AutoGen). This is more important to us than RAG experience alone; strong RAG skills without proven agent-building experience will not be sufficient.
• Evaluation & Benchmarking (critical requirement): Deep, critical understanding of evaluation methodology — designing benchmarks, choosing and interpreting metrics, and building automated eval pipelines that reliably drive accuracy improvements. You should be able to reason about the limits of a given eval method, not just run one.
• Fine-Tuning & Synthetic Data (critical requirement): Demonstrated experience fine-tuning models (LoRA/QLoRA), preparing training data, and generating synthetic data — plus the judgment to know when fine-tuning is and isn't worth it.
• Engineering Foundations: Strong Python for AI and backend work, with enough full-stack fluency (TypeScript/Node, some React) to integrate AI into product surfaces end to end.
• Systems Judgment: Scalable API design and a habit of building for graceful degradation, testability, and reproducibility.
• Senior Behaviours: Turns vague business problems into technical roadmaps in collaboration with product, design, and stakeholders; communicates results clearly to non-technical audiences; mentors peers; and takes accountability for outcomes.

Nice to Have

• Experience in legal-tech or another high-stakes, accuracy-critical domain.
• Multilingual NLP / retrieval experience.
• Model inference optimization (vLLM, TensorRT-LLM).
• Cloud infrastructure (AWS, GCP, or Azure) and containerization.
• Contributions to open-source AI projects or a strong portfolio of shipped AI applications.

🔄 Interview process

We’re proud of our multicultural team representing 37 nationalities! To ensure smooth communication, please apply in English (CV + Application Form).

• Introductory Video Call with Laurine, Talent Manager (30 min)
• Technical Interview with Dash, Head of AI (1h45)
• (Optional) Technical Interview part II, with Dash, Head of AI and Akshat, AI Engineer
• Half-Day at the Office + Lunch or Afterwork
• • Immersion with teams (1h30)
  • Culture Interview (45 min)
  • Team-Fit Meeting (45 min)
• Last call with Jean-Rémi, CEO, or Anna, VP of People (30 min)

Please note that, due to the nature of the sector we operate in, the final steps of our recruitment process include reference calls and a background check.

Need More Reasons to Join Us? ✨

• 💻 Enjoy a hybrid working organization that combines remote and on-site work (2 days).
• 🏖 Get 5 weeks of vacation each year, and take them whenever it suits you.
• 🩺 Receive 100% coverage of private health insurance for yourself and your children.
• 🍴 Enjoy 60% company-funded restaurant vouchers for your weekday meals (Swile).
• 😍 Participate in company-wide summits called JM Fest to connect and inspire.
• 🤸‍♂️Stay active with a co-financed ClassPass membership by accessing a variety of fitness and wellness activities.
• 🌍 Enjoy the flexibility to work from anywhere across the globe for up to 8 weeks per year.
• ✈️ Receive relocation assistance to help ease your transition to France.
• 📚 Profit from our support in ongoing training to continually expand your skills and knowledge.
• 💙 Last but not least: Experience a commitment to building a warm, inclusive, and diverse environment.

At Jus Mundi, we believe that diversity, equity, and inclusion are key to our success. Confidence can sometimes hold us back from applying for a job, but we’ll let you in on a secret: there’s no such thing as a ‘perfect’ candidate. We celebrate diverse backgrounds, experiences, and identities, and we encourage you to apply regardless of how you identify. Whether you’re early in your career or a seasoned professional, your unique perspective and skills are what matter most. Join us in building a workplace where everyone feels valued, empowered, and excited to contribute their best work every day.