Lead Full-Stack Developer

• Location:Paris, Châtelet - Hybrid (2 days on-site / 3 days remote)

• Contract: Full-time (permanent)

• Team: Technology

• Compensation: €72,000-€92,000 gross annual base + BSPCE (equity), depending on level

About Mendo - and why this matters

We're living through the biggest technological shift since the internet. Generative AI is changing how people work - yet most teams barely scratch the surface, unsure how to turn the hype into real, everyday value. Closing that gap is exactly what Mendo does.

Mendo is the AI Transformation Platform for enterprise clients. Rather than adding yet another tool to the stack, we work right inside the AI tools teams already use - Microsoft 365 Copilot, ChatGPT, Gemini, Claude, and internal agents. From there, we guide people toward proven use cases, certify their skills, and give organizations a clear view of what's actually driving value.

And it's working. We support 100+ enterprise clients - including EY, PwC, Crédit Agricole, SNCF, La Poste, ENGIE, Groupe SEB, and Novo Nordisk - with 200+ use cases live, a user NPS of 64, and 3x GenAI ROI within months. We've raised €12M following our Series A and we're scaling fast.

Join us and you won't just ship software - you'll shape how the world's largest organizations adopt the defining technology of our era, and help keep people at the center of the AI revolution rather than left behind by it. We believe humans have a vital role to play in this revolution, and we're building the platform that keeps them there.

Core mission

Lead full-stack development within one of Mendo's technical squads. As Lead Dev, you'll manage a small team of developers, own the quality and technical direction of your product area, and stay hands-on in the code.

We're scaling fast - more squads, more product surface, more clients - and we need strong leads to help us grow the engineering org without losing our bar for quality. You'll be one of the people we count on to build the teams of tomorrow.

Your squad assignment will be defined based on your profile, your technical interests, and our product priorities.

Key responsibilities

1. Lead delivery and technical direction

• Drive the development of full-stack features for your squad, end to end.

• Make architectural decisions aligned with the product roadmap and our scalability goals.

• Stay hands-on while setting the technical direction for your product area.

• Own the release lifecycle for your squad's work.

2. Own code quality

• Run rigorous, constructive code reviews and uphold the team's quality bar.

• Identify and prioritise the refactoring and testing needed to keep the codebase healthy.

• Balance shipping new features with continuous improvement of existing code.

3. Shape the roadmap and prioritise

• Partner with Product to build and own your squad's roadmap.

• Prioritise the work, break it down, and delegate it across the team.

• Keep delivery on track by balancing scope, quality, and timelines.

4. Grow and scale the team

• Mentor and level up the developers in your squad.

• Help us hire: contribute to sourcing and interview loops as we scale the org.

• Instill a culture of craftsmanship, knowledge-sharing, and continuous improvement.

Tech stack

• Language: TypeScript, end to end.

• Backend: NestJS and Fastify, with tRPC for type-safe contracts.

• Frontend: React with Vite, Tailwind, Zustand, and TanStack Query.

• Connectors / clients: Chromium-based browser extensions and an Electron desktop connector that embed Mendo inside Microsoft 365 and browser AI tools.

• Data: MongoDB (Mongoose) and Redis.

• Infra & deployment: Azure / AKS with Helm, Docker containers, GitHub Actions CI/CD.

• AI in the product: we train and deploy our own language models on client machines (on-prem), alongside OpenAI APIs and a Python ML service (sentence-transformers, scikit-learn) for search and similarity.

• AI-augmented engineering: Claude Code / Cursor, MCP tooling, and internal AI agents are part of the daily workflow - not a bonus.

This stack is always evolving, and we're counting on you to help us evolve and improve it.

Required skills

Experience & expertise

• Deep, hands-on experience building full-stack applications in TypeScript.

• Strong command of modern frontend (hooks, state management, performance) and Node.js backend frameworks.

• Experience with multi-tenant SaaS architectures and the scalability challenges that come with them.

• Comfortable with containers, CI/CD pipelines, and DevOps practices.

• Solid grasp of testing principles (TDD, unit, integration).

• Experience deploying and operating SaaS in production.

Leadership & ways of working

• Proven technical leadership - demonstrated experience leading and growing a team of developers.

• Effective code reviews, mentoring, and clear technical documentation.

• Ability to balance technical quality against business and deadline constraints.

• Excellent command of French and English, both technical and professional.

Mindset

• Natural rigor and a feel for software craftsmanship.

• A born teacher who enjoys helping others grow.

• Genuine curiosity for new technologies and best practices.

• Strong team spirit, autonomy, and a sense of priorities in a fast-moving scale-up.

• Alignment with our values: Learning, Innovation, Excellence, Kindness, Transparency.

What we offer

• Competitive package: €72,000-€92,000 base depending on level, plus BSPCE (equity) under our Series A policy.

• Real impact: a key role in a company on track for 4x growth this year.

• A scaling org: we're actively growing our teams - fast, merit-based career progression for the right leads.

• A learning environment: a team passionate about new technologies and generative AI.

• A stimulating workplace: a young, supportive culture where everyone helps each other.

• Flexibility: a hybrid 2-day/3-day remote model.

• Meaningful mission: helping make AI accessible and impactful for everyone.