(Senior) Software Engineer (f/m/d) - Data Science/Machine Learning

Permanent contract, full-time or part-time, Cologne / Darmstadt / Düsseldorf / Remote

Who we are


We operate Kaufland.de: Several thousand sellers and millions of products make us one of the fastest growing online marketplaces. Our work is characterised by a dynamic corporate culture, with a start-up mentality and the opportunities offered by a large corporation in the background. We combine knowledge and many years of experience in e-commerce with flat hierarchies and a highly motivated team. Whether you're an intern or a teamlead: We take every idea seriously, because we want to work together in shaping the future of e-commerce!

We love flexibility! We offer you the best environment to work in a flexible and focused way: You decide whether you want to work in our office in Cologne // Darmstadt // Düsseldorf while at the same time having the opportunity to work remotely (Germany). We want to offer you the most attractive workplace in e-commerce and a maximum of flexibility for your personal work-life balance.

Day-by-day, our development team of about 250 experts pursues the goal of creating the best-possible customer shopping experience for the Kaufland.de marketplace. We are here to inspire millions of customers, to help them find, purchase and get the things they love. To enrich the lives of our customers, we collaborate in cross-functional teams, in which product owners, product designers, frontend and backend engineers, data scientists and lean managers join forces. Details regarding the challenges of the respective product areas can be found here.

Your tasks – this is what awaits you in detail

  • You drive the further development of our marketplace based on all things data: You will work closely with our data scientists and other software engineers to bring our machine learning and data science smartness into production.
  • You help build new front ends and highly scalable, low-latency backends.
  • You will have the opportunity and freedom to mix and match existing machine learning models, to come up with completely new features and ideas. You make our shopping experience even more enjoyable for our customers: To give an example: You think our existing recommender systems can be used to create a new end-user feature? Then you would just go build the frontend and BFF layer yourself and start an A/B test.
  • You will be responsible for finding the best approaches and architectural solutions to fulfill our non-functional requirements.
  • If you are curious, there will be plenty of time to learn about data science methods yourself along the way.
  • You will have the opportunity to work directly with an amazing team and on a vast array of data science challenges, bringing new advances out of academia directly into production.
  • This is not a “catch things we throw over the fence” position: You will be part of projects from start to finish and work with a team of data scientists that is proud to maintain their own microservices.

Your profile – this is what we expect from you

  • You have a university degree in computer science, information systems, mathematics, or the like.
  • You consider yourself a full-stack developer, being able to work with frontend and backend technologies alike.
  • You have a very good understanding of JavaScript and the surrounding ecosystem, including Node.js and modern frontend frameworks such as Vue, Angular, or React.
  • You have experience with modern databases, caches, and usage patterns for them.
  • You consider yourself a craftsperson. You value quality, clean code, and solid (pun intended!) architecture patterns.
  • You view making sense of other people’s code as a learning opportunity and are willing to dive into a bit of PHP/Go/Python or other languages to make small changes to our existing codebases so they become usable for your own services.
  • A beginner’s level understanding of machine learning or experience in a data-centric team is required. Curiosity for the field is a big plus.
  • You have a very high capacity for abstraction, a sound algorithmic understanding and are used to find your way around various data sources.
  • You have excellent communication skills, are willing to embrace our company culture and values and enjoy working in an international, English-speaking team.

What we offer

  • Work as you feel comfortable! We offer you the best possible flexibility in terms of working hours and location. Create your own work-life!

  • A highly-motivated and qualified team from different fields and numerous nations

  • The future is digital - Develop the e-commerce of the future with us and work on a product with millions of users with a broadly-based technology stack

  • Power meets dynamic - flat hierarchies and start-up mentality meet the power of a big corporate group and offers you an agile and secure working environment at the same time

  • Free choice of hardware – we provide you with the development environment of your choice

  • Personal & team growth: We love to have flexibility in terms of working location, but we also believe that personal interactions are important. That’s why we organize company events, and cover the costs to bring you there and to other (approved) get togethers with your peers. The same applies to conferences and other learning opportunities. We want everybody to grow personally and professionally, as a team and as a company

  • Top conditions at the Urban Sports Club for fitness, team sports, yoga and more

Check out our Principles & our blog for even more insights into our company culture!

Refer an Engineer Program

You want to work for us, but not without your dearest colleague? Join us as a team and earn money by referring your buddy for one of our open Tech positions! Depending on the level we offer a bonus up to 1.300,- € per referral, which will be paid after successful recruitment (the first part with your first salary, the second part after your buddy passes the trial period).
Why are you the perfect fit for this position? Don't bother with cover letters - we're interested in facts and figures!
As we have very international teams, we would highly appreciate it to receive your CV or profile link in English.
Apply here

Your contact person: Vivian Förder

Kaufland e-commerce
Kaufland e-commerce Services GmbH
Postal ​address:
Habsburgerring 2
50674 Köln

Offene Stellen