Senior Backend-Engineer C# (f/m/d) - Cologne, Paderborn oder remote


is Germany's best-known AI company. We develop neural networks to help people work with language. With DeepL Translator, we have created the world's best machine translation system and made it available to everyone free of charge. Over the next few years, we aim to make DeepL the world's leading language technology company.

Our goal is to overcome language barriers and bring cultures closer together.

What distinguishes us from other companies?

DeepL (formerly Linguee) was founded by developers and researchers. We focus on the development of new, exciting products, which is why we spend a lot of time actively researching the latest trends and technologies. We understand the challenges of developing new products and try to meet them with an agile and dynamic way of working. Our open and positive workplace philosophy enables employees to feel comfortable and thrive in their roles. In our daily work we use modern technologies - not only to translate texts, but also to create the world's best dictionaries, and solve other language-related problems.

When we tell people about DeepL as an employer, reactions are overwhelmingly positive. Maybe it's because they have enjoyed our services, or maybe they just want to get on board with our quest to break down language barriers and facilitate communication.

Work wherever you want

Whether you would like to work from home or from one of our offices in Cologne or Paderborn, the choice is yours. No matter where you choose to work from, our way of working is designed to make you an integral part of the team. This is why we are looking for outstanding employees from all over Germany, the Netherlands or Poland.

What will you be doing at DeepL?

Thanks to our unique neural networks, DeepL is able to deliver the world’s best translation quality. In order to keep it that way, we are constantly improving our apps and adding exciting new features - and this is where your experience in developing sophisticated software comes in. 

You will be developing C# backend services (running on .NET Core on Linux) for products that help millions of people in their everyday lives. You will be part of a highly motivated team that values easy to maintain and efficient code. Important design decisions are made by the whole team in open discussions.


Your responsibilities

  • Design and implement reliable, scalable and efficient backend services for DeepL's products
  • Contribute to monitoring and debugging the services in production, e.g. by defining expressive metrics and ensuring informative logs
  • Integrate DeepL with external services for authentication purposes
  • Collaborate across teams to define shared interfaces and ensure smooth operation in production

What we offer

  • Interesting and challenging software development work on a product that is already used by over 100 million people
  • A small, effective and highly skilled team enjoying mutual trust and very short decision-making processes
  • Code reviews and a focus on high quality
  • Meaningful work: We overcome language barriers and thus bring cultures closer together
  • Lots of flexibility and a comfortable office in Cologne or Paderborn (or suitable equipment for your home office)

About you

  • Several years of software development experience
  • Strong proficiency in C# and .NET Core
  • Solid understanding of algorithmic complexity and common data structures
  • A degree in computer science or comparable, alternatively several years of professional experience in software development
  • Fluent in English, knowledge of other languages is a plus

Ideally, you have one or more of the following qualifications:

  • Deep knowledge about building and optimizing high-traffic ASP.NET Core services for Linux
  • Experience with highly available SQL or NoSQL databases
  • Experience implementing Single-sign on (SSO), e.g. with SAML
  • Experience hosting services on AWS


We are looking forward to your application!