Full-Stack Engineer, Growth

📍 Location: Paris, France

🛠 Tech Stack: JavaScript (Full Stack), Ruby, HTML, CSS

🚀 Experience with: Cursor, AI Agents, Prototyping

About Lago

Lago is on a mission to redefine metering and billing for modern businesses. We build open-source, developer-first infrastructure that empowers companies to handle complex usage-based billing models with ease.

We move fast, iterate constantly, and thrive on innovation. Now, we’re looking for a Growth Engineer to supercharge our acquisition and activation efforts.

What You’ll Do

We've done "things that don't scale" and learned what worked. Now we need someone to help us scale ourselves, through software and AI.

We've scaled the Growth Engine of Qonto.com before and know how this role is pivotal. And it's only going to be even more impactful with AI.

•Engineer growth experiments: Build and ship rapid prototypes to test acquisition and engagement ideas

•Develop AI-powered tools: Leverage Cursor and AI Agents to automate workflows and optimize internal tooling (for Sales, Marketing, Customer Success)

•Own full-stack projects: Work across JavaScript, Ruby, HTML, and CSS to build growth-driven projects

•Analyze and iterate: Use data and user feedback to refine experiments, improve onboarding, drive adoption, and feature expansion

•Collaborate closely: Work with product, marketing, and engineering to scale impact efficiently.

What We’re Looking For

•Full-Stack expertise – Strong experience with JavaScript (React, Node.js), Ruby, HTML, and CSS ; at least 3years+

Ideally you have shipped products on your own, with very little supervision, in your day job or in your free time.

•AI/Automation mindset – Experience using Cursor, and ideally, you’ve built and deployed AI Agents before. If you haven't built with AI on your spare time, out of curiosity, you're probably not the right fit.

•Prototyping skills – Ability to quickly build and iterate on functional prototypes and growth experiments.

•Growth-driven engineering – You’re not just a coder; you understand growth loops, conversion funnels, and acquisition tactics.

•Startup energy – You thrive in fast-moving environments and love shipping impactful projects: learning and failing fast to "get it right".

Bonus Points

✅ Experience working on open-source projects

✅ Passion for billing, fintech, or developer tools

✅ Contributions to AI or automation communities

Why Join Lago?

🔥 High-impact role: Your work will directly influence user adoption and revenue growth.

💡 Cutting-edge AI & automation: Work on the latest tools like Cursor and AI Agents.

🌍 Hybrid & flexible culture: Work from our Paris HQ with a smart, driven team.

🚀 Backed by top investors: We’re well-funded and growing fast.