Fullstack Software Engineer - LCA Team

The fashion industry is responsible for 5–10% of global greenhouse gas (GHG) emissions. As pressure for climate action grows, more companies are turning to carbon management tools. But most platforms are generic, lacking the depth needed for driving real change in fashion.

That's why we built Carbonfact , the only environmental data platform tailored for the textile and fashion industry. Our platform automates product-level life-cycle assessments (LCAs) and company-level carbon accounting, helping brands measure, model, and reduce their impact with precision.

We've raised $17M from top-tier investors including Alven, Headline, and Y Combinator, and we're already trusted by leading brands like Carhartt, GANNI, On, Burton, Armedangels, Jack Wolfskin, and many more.

What you will do

As a Software Engineer on our LCA team (led by Leonardo ), you'll build and scale the engine that turns raw supplier and product data into environmental footprints. It already computes more than 2 million LCAs per day , and our ambition is to make it the most scalable LCA engine in the world.

The LCA team sits at the intersection of our science, data, and engineering teams. You'll turn methodology into code with our scientists, work on the pipelines that feed the engine with our data team, and ship the results to customers with the rest of engineering. You'll also talk directly to our most advanced customers and prospects, who want to understand exactly how a number was produced.

The LCA team is directly responsible for the calculations, ensuring trust with our customers. Every footprint we publish ends up in a customer report, a regulatory filing, or a product page. That asks for a high level of rigor: in how we model, how we test, and how we explain our results.

Engineering at Carbonfact

Our engineering team is lean, autonomous, and product-focused.

• Lean : we believe that a strong small team can achieve a lot. We keep headcount low and impact maximal. We prioritize hard, cut corners intentionally, and try to be pragmatic on where we invest our time.

• Autonomous : we work across the full stack and beyond (e.g doing bits of data engineering, talking directly to customers). We have very little management overhead, close to no meetings, and the power and responsibility to drive our scopes from initial ideas all the way to the finish line. But autonomous doesn't mean alone: we pair, discuss, review PRs, and share struggles and solutions as a team!

• Product-focused : we respect and leverage technical expertise, but view software as a means to an end, not a goal in itself. We keep things simple and maintainable, buy instead of build when we can, and carefully invest in complexity. We ship fast and deliver improvements to customers as often as we can.

We work in 5-week cycles following the Shape Up method, with 1 cooldown week for tech debt and loose ends.

During cycles, we focus on delivering bets - projects with a set time appetite . Engineers own both project management and delivery autonomously, with peer support.

Technical stack

Every day, our software engineers write Typescript , SQL , and more rarely dig into some Python code for the parts of our infra we share with our Data team.

We use:

• Node.js and Nest.js on the backend

• React and Next.js on the frontend

• BigQuery for the data warehouse

• Postgresql for the application database

We deploy on Google Cloud, Vercel and Cloudflare, using infrastructure-as-code (terraform). We are well equipped with various tools to speed us up and handle the busy-work for us: Sentry for monitoring, Cubic for AI code reviews, Aikido for security scanning, etc.

We believe that AI will play a major role in software development and operations, and we leverage the latest technologies to help us achieve more with less. Our team is empowered with generous access to the best tools on the market, and we build and exchange skills and best practices both within the engineering team and across the whole company.

Who you are

• At least 2 years of experience building software products, with a certain amount of autonomy.

• Fullstack background with a solid knowledge of TypeScript

• Rigorous with numbers: you double-check your results, you get uncomfortable when something is off by a few percent, and you can explain how a computation works

• Curious about what we do, and excited by the idea of building the world's most scalable LCA engine. No prior LCA or sustainability knowledge needed. We'll teach you

• Pragmatic, product-minded, and customer-obsessed

• You have strong verbal and written communication skills in English. You'll sometimes be in front of our customers.

• Based in Paris or willing to relocate

Work environment

• A transparent, collaborative, high-agency culture rooted in Carbonfact's Principles here

• AI-first tooling: generous access to frontier AI models, Claude Code, GitHub Copilot

• MacBook, headset, and all the modern essentials

• 100% coverage of premium health insurance with Alan

• Fitness and commuter benefits

• Annual learning budget to support professional development

• Team retreats and social events multiple times a year

• Transparent compensation framework with level-based salary and equity; promotions tied to impact and performance; the salary range for this role is €59K - €76K per year commensurate with experience

• Compelling equity package with employee-friendly exercise rights

Hiring process

• Submit your application online

• Screening call with our Talent Partner to explore mutual fit

• Systems design interview with Leonardo , hiring manager who leads the LCA team

• Pairing Interview with Gaby , who leads our Surface (Platform & UX) team

• Onsite interview loop:

  • Project presentation

  • Validation interview with Romain , CTO and co-founder

  • Principles interview with Martin , CPO and co-founder

• Final debrief and reference calls

• If there is mutual interest to move forward, we'll extend you an offer to join our team