Staff Engineer - Paris H/F - Jus Mundi

Le besoinCompanyJus Mundi is a Paris-based legaltech founded in 2019 with one mission: power global justice, by making international law and arbitration genuinely accessible through data and AI.The platform centralises the most comprehensive collection of arbitration material in the world: awards, treaties, case law, institutional rules and publications, largely multilingual and until now scattered or locked away.Around 100 people, 39 nationalities, and customers in more than 100 countries. Offices in Paris, New York, London, Singapore and Mexico City.8 figures ARR, 35 percent of it from the US, with growth targeted at 70 to 75 percent per year.A 22M$ Series B closed in late 2024, led by Acton Capital and True Global Ventures with C4 Ventures and FJ Labs following, one of the largest rounds raised by a European legaltech.Exclusive data partnerships with more than 100 leading arbitration institutions, including a 2026 collaboration with the Court of Arbitration for Sport.
ProductsJus Mundi: multilingual search across international law and arbitration, so a lawyer finds in minutes what used to take days of manual research.Jus AI: an agentic assistant built specifically for arbitration. Natural language questions with cited answers, document analysis, summarisation, translation, cross-jurisdiction comparison, and agents that take over repetitive work.Jus Connect: the network and data layer. Identify arbitrators, counsel and experts, map who worked on which case, check conflicts of interest, build shortlists.The product is opening up beyond its own interface: in March 2026 Jus Mundi and Legora announced the first agent-to-agent integration in arbitration, rolling out through 2026.Next horizon: agentic systems that reason over private client data and connect to internal databases, the web and partner sources.Why nowThe company is deliberately simplifying. An early microservices architecture that was never justified by traffic volume is being brought back toward a pragmatic, more monolithic design.Data volume is about to change scale: from roughly 100k documents today to several hundred million over time. The engineering decisions taken this year will be lived with for years.A new CTO joins in September 2026, with the founding CTO staying involved through the transition. The technical standards of the next phase are still being written.Engineering has grown to around 25 people across 5 squads with no dedicated technical reference above squad level. This role is created to close that gap.AI-assisted development is being rebuilt into the way the whole team works, and this role helps set that standard rather than inherit it.For a staff engineer, that combination is rare: a full transformation to run end to end, with real headroom for a bigger role afterwards.The roleYou join the Platform team, the only fully transverse squad, and act as a technical force multiplier across every product and engineering squad.The north star is zero-friction delivery: shipping business value fast and securely, through simple and standardised engineering practices.Your first mandate is the new engineering framework: the standards for reliability, security, testing and deployment that every squad will work to.This is an individual contributor role with no direct reports, positioned at level 4 to 5 on the six-level engineering ladder: autonomous, and making others autonomous.Half the value of the role is influence. You become the reference developers come to, and the working example of the product-minded engineer Jus Mundi wants across its teams.You report to Yohan Daddou, Head of Infrastructure, who is also the hiring manager for the role.What you'll doDefine and roll out the engineering framework across squads: reliability, security, testing, deployment.Build a testing environment developers actually trust, and keep it alive instead of letting it decay.Drive the architectural transition away from immature microservices, deciding service by service what gets reintegrated and how.Work inside the product squads on their developer experience: tooling, CI/CD, feedback loops, everything that quietly slows a developer down.Call out tech for tech's sake. When a squad over-engineers, bring it back to the simplest solution that serves the customer.Coach engineers toward a product builder mindset, mostly by example and in the flow of their work rather than through formal training.Take on the critical stack work nobody has time for: PHP and Symfony upgrades, third-party library migrations, infrastructure hardening.Step into critical incidents and drive them to resolution.Write production code across several domains, switching context between technical subjects without losing depth.Ways of workingAn EPD organisation (engineering, product, design) built on autonomous squads, with product and tech alignment treated as a first-class concern.AI-assisted development is not optional here: agentic coding tools are expected in daily practice and the team is actively rethinking its methods around them.A six-level engineering ladder is being rolled out, with explicit expectations at each level.Pragmatism over purity. The past years of tech for tech's sake are openly acknowledged, and the current direction is simplicity, reuse and reintegration.High technical standards, a fast-moving environment, and communication treated as an engineering skill rather than a soft one.TeamAround 25 engineers in 5 squads: Platform (infrastructure, security, developer tooling), Legal Data Collection, Search, Core AI, and User Lifecycle and Growth.Platform is 3 engineers plus an engineering manager. It is your home squad, not your scope: most of your time is spent in the other squads.Day-to-day collaborators: Yohan Daddou (Head of Infrastructure), Mathieu Caudron (Tech Lead Manager), the squad EMs and PMs, the Core AI team, and security stakeholders.Leadership: Jean-Rémi de Maistre (co-founder and CEO), Thomas Latterner (co-founder and CTO), Ayushman Dash (Head of AI), Stéphane Altounian (VP of Product).39 nationalities, and a team that is international by default rather than by policy.StackBackend: PHP, SymfonyAlso in production: Node.js, NuxtArchitecture: microservices being reintegrated toward a pragmatic monolithInfrastructure: Kubernetes, infrastructure as code, CI/CD, observabilityAI: in-house AI layer powering Jus AI, agentic reasoning over the arbitration corpusData: large-scale multilingual legal document processing and searchTooling: agentic coding assistants (Cursor, Claude Code and similar) in daily usePHP is the core stack but not a gate: the team hires on engineering maturity and assumes a strong engineer picks up a new language.At a glanceCompensation: 80-110K€ + equityLocation: Paris 8e, avenue HocheRemote: 3 days/week, 8 weeks intl. flexContract: Full-time, permanentReporting to: CTO

Profil recherchéAround 10 years of engineering experience, including several years at senior or staff levelStill hands-on in production, and able to raise the level of everyone around you at the same timeJudgment over stack: pragmatism, the instinct to reuse and simplify rather than rebuildComfortable reasoning out loud and bringing others into your thinking as you goPHP and Symfony experience welcome, not requiredAgentic coding tools part of how you already work