Backend Developer (Python, Java)
Confirmed on the employer's own hiring board on Nov 12, 2026. First seen by Alion on Nov 12, 2026. Lefebvre Sdu scores B on the Alion truth index.
Legal AI is only as good as the knowledge behind it. At Lefebvre Sdu, we've been building that knowledge for over 200 years. Day in, day out. Law by law. Word by word. As the Dutch heart of Lefebvre Group, the European leader in legal and tax knowledge, we're also developing our own platform: GenIA-L, where lawyers and tax advisors don't just get an answer, but an answer they're willing to attach their name to. More than 75,000 professionals use it daily, generating over 100 million euros in ARR across Europe. We're looking for a Medior Backend Developer to help build that.
HOW YOU'LL MOVE US FORWARD
Lawyers and tax advisors ask a question in GenIA-L and get a reliable answer. That answer is what they see. What you build is everything needed to make it happen: the backend. These are the systems and connections that keep our AI product fast, secure and reliable. You join the AI team and work with our AI engineers every day. They make the product smart; you make sure that intelligence actually reaches the user. After six months, you know the code well and have shipped several new features. After that, you choose the direction you want to grow in: more towards AI, for example by improving the quality of our AI answers, or more towards DevOps, for example by improving how we automatically test and release software.
You build and maintain the backend of our main AI product, together with our AI engineers.
You build APIs and services: the connections that let the different parts of the platform talk to each other.
You keep an eye on code quality and make sure we follow good practices and standards.
You monitor and maintain our live applications and fix problems when something goes wrong.
You bring your own ideas on how to improve the product and the way we work.
You are proactive, enthusiastic, and take initiative.
You communicate clearly and confidently, conveying information in a concise and engaging manner.
Requirements
WHAT WE'RE LOOKING FOR
You pick up your work independently. You don’t need much guidance, but you know when to involve a colleague.
You have opinions and you are not afraid to share them.
And you enjoy working with AI specialists on a product that is still very much in development.
At least 3 years of experience building Python applications that run in production and are actually used by customers.
Experience with FastAPI and Pydantic. Experience with LangChain or LangGraph is a plus.
You have built production-grade APIs that work reliably for real users.
You work independently within a team and don’t need hand-holding.
Knowledge of Postgres, GraphQL or MongoDB is a plus.
Some DevOps knowledge is nice to have, for example working with GitHub Actions and Helm.
WHAT YOU'RE SIGNING UP FOR
You join the AI team with one other backend engineer, three AI engineers and a Product Owner. You also work closely with the search team, the frontend team and our backend and AI leads. You report to our Lead Backend Engineer. You get a lot of freedom and room for your own opinions and ideas, in a fun team with a good work-life balance. And you can grow into a Senior or Lead Backend Engineer role.
A monthly base salary up to €5500 and a standard 36-hour working week.
An end-of-year bonus of 4% of your gross annual salary and a variable profit share of up to 6% of your gross annual salary.
23 holidays and a 12% personal benefits budget, of which 8% is holiday allowance and 4% you can spend freely, for example on extra days off.
A good pension plan through PGB, including additional partner insurance.
A travel allowance of €0.25 per kilometre or a public transport allowance, plus an attractive bike scheme. For employees who travel less than 10 km or more than 60 km, we have an adjusted arrangement.
Hybrid working: two days a week at our office in The Hague, on Tuesday and Thursday.
Room to grow. In your field, in your role, in the organisation.
WANT TO KNOW MORE?
We'd love to tell you all about the team and the role. Send us your CV and you'll hear from us within a few business days. Have a few questions first? Message or call Nadine at 0628556265.
A reference check and a VOG (certificate of good behaviour) are part of the selection process.