we are cronn

We are cronn – a Bonn-based software development company with branches in Hamburg and Białystok, Poland. Software development is our passion. We trust in Java, OpenSource and, last but not least, in our experienced team. All of this we deploy to bring our clients software that is key to their business, or to professionally consult them in issues regarding architecture, tools or approaches.

cronn locations marked on mapThe three cronn office locations - Bonn, Hamburg and Białystok - marked on a map

What tasks await you

  • Backend development in Java
  • Frontend development share available for those who like to try and lean new things
  • Learning path to explore together with experienced developer assigned to you as your mentor
  • TDD, Pair Programming, Code Reviews
  • Small and experienced teams where you can learn by doing
  • Development of business-critical, customer-specific software solutions
  • Knowledge Sharing, Craftsmanship, Continuous Improvement


  • You know basics of Java
  • …but you are still willing to learn and get hands-on experience
  • Quality, agility, open-mindedness and passion describe your working style
  • Clean Code and Software Craftsmanship are no foreign words for you
  • You can communicate in English in speaking as well as in writing
  • You are going to love writing tests as much as productive code
  • You have successfully completed a subject-related course of study (or are in the process of doing so)
  • You are willing to work on-site in our cool office in Białystok

… then we want to get to know you!

When, on top of this, you want to gain experience with a few of the following tools and technologies

  • Spring (Boot/Cloud), Hibernate/JPA
  • REST, HATEOAS, Webservice
  • Gradle, Git, SonarQube, Jenkins
  • JUnit, AssertJ, Mockito, Testcontainers, Cucumber
  • MariaDB, Oracle, PostgreSQL, MongoDB
  • Docker, Kubernetes
  • Machine-Learning, Neural Networks, Artificial Intelligence
  • Amazon Web Services, Microsoft Azure, Google Cloud
  • Microservices
  • Reactive Programming

… then we absolutely must get to know you!


Apply now!

Does this job offer suit you?
Then we look forward to receiving your application through our application form!

Apply now Our benefits

Our benefits

Work at cronn

Our teams and our abilities

Our catchphrase is „wir entwicklen software“ – developing software brings us joy. We believe in Software Craftsmanship, good code and score with a team that brings both competence and a healthy attitude to the table.​

Interesting and challenging software development projects

Our projects are laid out within in a wide scope of fields. We show the same enthusiasm for start-ups as we do for multinational corporations. We embrace challenges and believe in development and growth.

Hardware and operating system according to your preferences

Because you know best what you like to work with. On top of that all of our work stations are equipped with height-adjustable tables and ergonomic chairs.​

Further training opportunities

We encourage personal growth with a yearly further education budget and two days exceptional leave for you to use on conferences, workshops or certifications – alone, with a colleague or with the whole team.​

Flexible working hours

We want cronners to find their best possible work-life balance: that’s why we have flexible working hours and home office days.

Employee events

No later than at your first Christmas party you’ll get to witness how much we enjoy celebrating together. However, until then there are many other events held throughout the year: beer tastings, summer parties, runs, short trips, cronn sports clubs or our weekly afternoon beer. Open – but not obligatory! – for all.​

Participation in conferences and engagement

We love to share our knowledge and actively participate in local communities such as the Java User Group or the Usability Testessen. You are welcome to influence and shape this network.​

A cool office

It’s easy to feel comfortable in our modern, sunny and well-located office. We have good tea and coffee (really good!) and unlimited soft drinks. We also make sure there’s always something to nibble on, be it sweet, salty or healthy.​


Questions regarding you application?
Maja will be glad to answer them all:

  +48 608 537 643

Unsolicited application

No fit? No problem

Haven’t found a job offer that exactly fits your profile? Don’t worry – we welcome unsolicited applications.

Send in you application now