Senior Backend Developer - Java 17

About Twoday

Twoday is the leading digital transformation partner in Northern Europe with a global presence. With approximately 3,000 technologists, we collaborate with some of the most recognised private and public organisations to deliver cutting-edge digital solutions. Our deep industry expertise spans Data & AI, software development, digital experiences and business applications.

Our team operates across the Nordics and Lithuania, supporting more than 8,000 customers on their digital transformation journeys.

Senior Backend Developer - Java 17

About the role

We are looking for a Senior Backend Developer to join a long-term public sector digitalisation programme in Denmark.

You will become part of an experienced Scrum team responsible for developing and maintaining business-critical backend services that support modern frontend applications and complex digital workflows. The role combines hands-on backend development with code reviews, testing and close collaboration with frontend developers, testers, Product Owners and Business Analysts.

This is an opportunity to work on large-scale, long-lived solutions where quality, maintainability and collaboration are key.

Responsibilities

• Develop and maintain backend services using Java 17 and Spring Boot

• Design and implement REST-based APIs and integrations

• Participate in code reviews and contribute to high engineering standards

• Test and validate both your own and your colleagues' code

• Collaborate closely with frontend developers, testers, Product Owners and Business Analysts

• Participate actively in Scrum ceremonies, refinement sessions, estimation and solution design

• Contribute to the continuous improvement of the team's architecture and development practices

Technical environment

You will work with technologies including:

• Java 17

• Spring Boot

• Hibernate

• PostgreSQL

• Groovy / Spock

• REST / JSON

• XML

• IntelliJ IDEA

It is an advantage if you also have experience with:

• SOAP UI

• YAML

• WSL / Linux

• Gradle

• Elasticsearch

• Kafka

• Jenkins

• Rancher

• Helm / Helmfile

Required qualifications

• Strong professional experience with Java development: Java 17 or similar modern versions

• Solid experience with Spring Boot and Hibernate

• Experience developing REST APIs

• Experience working with PostgreSQL or other relational databases

• Experience working in Scrum teams

• Experience reviewing and testing code

• Fluent Danish, both spoken and written

• Ability to work onsite full-time in Copenhagen

Nice to have

• Experience with Groovy / Spock

• Experience working with containerised environments and deployment tooling

• Experience from large enterprise or public sector solutions

• Experience collaborating closely with frontend teams

Additional information

Please note that the customer does not permit the use of AI-assisted or agentic programming tools during development.

Team

You will join a cross-functional Scrum team consisting of:

• Scrum Master / Business Analyst

• Product Owner / Test Manager

• Four Developers / Testers

The wider department consists of approximately 40 people, including both permanent employees and consultants.

Practical information

• Location: Copenhagen (onsite full-time)

• Employment: Permanent position

• Start: As soon as possible

What We Offer

Twoday has modern offices across 30 locations in Norway, Sweden, Denmark, Finland, and Lithuania. We offer a strong and unique social working environment with highly engaged colleagues.

For the right candidate, this is an opportunity to take on a central role with exciting professional development opportunities in an international and innovative technology organisation delivering advanced digital solutions and services.

You will also have the flexibility to occasionally work from one of our main offices in Oslo, Stockholm, Copenhagen, Helsinki, or Vilnius.

Diversity & Inclusion

Do you not meet every single requirement? Studies show that women and underrepresented groups are often less likely to apply for a role unless they meet every criterion. At Twoday, we are committed to building an inclusive and diverse workplace. If you are excited about this opportunity but your experience does not perfectly match every qualification, we still encourage you to apply.