Senior Java Developer
Confirmed on the employer's own hiring board on Nov 12, 2026. First seen by Alion on Sep 7, 2026. Twoday Oy scores A on the Alion truth index.
Twoday is the leading digital transformation partner in Northern Europe with a global presence. With approximately 3,000 specialists, we collaborate with some of the most admired private and public organisations to deliver cutting-edge digital solutions. Our expertise spans software engineering, Data & AI, cloud platforms, digital experiences and business applications.
We are now looking for a Senior Platform Engineer to help transform a large-scale development and deployment platform from traditional DevOps into a modern AI-assisted and agentic engineering setup.
Permanent position at Twoday | Copenhagen
Senior Java Developer
Would you like to develop new digital solutions that support collaboration across the Danish criminal justice system? We are looking for an experienced Java Developer to join Twoday, with your first assignment being for a major public-sector customer in Copenhagen.
Your role
You will join a team developing a new solution that supports digital collaboration across public authorities. Your primary focus will be backend development in Java, although you will work closely with a frontend built in Vue.js.
Your responsibilities will include:
Developing new backend functionality in Java and Spring Boot
Designing and implementing APIs and event-driven integrations
Writing automated unit and integration tests
Working with database changes and data models
Contributing to code reviews, technical discussions and solution design
Troubleshooting and maintaining quality throughout the delivery process
Collaborating with developers and stakeholders across organisational boundaries
Technology stack
The core backend stack includes:
Java 25
Spring Boot 3.5
OpenAPI 3
Kafka
Spock
Liquibase
Microsoft SQL Server
Azure DevOps
Docker
Helm
Gradle
The frontend is built with Vue.js 3.5, TypeScript, pnpm, Quasar, Vite and Cypress. Frontend experience is not required, but experience with Vue.js would be an advantage.
A limited part of the solution integrates with the Danish Police using JAX-WS, Apache CXF 4, SOAP and XML. Experience with these technologies would be beneficial, but is not a requirement.
About you
We expect you to have:
Several years of professional Java development experience
Strong hands-on experience with Spring Boot
Experience developing APIs and integrations
Experience with automated testing and modern development practices
An understanding of CI/CD, containerisation and deployment
The ability to work independently while contributing actively to the team
Strong communication skills and an interest in understanding complex business domains
Professional fluency in Danish and English
Able to work full time onsite in Copenhagen
Experience with Kafka, Spock, Liquibase or public-sector solutions would be an advantage.
Working at Twoday
At Twoday, you will become part of a strong professional environment where collaboration, knowledge sharing and high-quality software development are central. You will work closely with experienced colleagues while helping our customers digitalise complex and socially important processes.
The position is based in Copenhagen and requires full-time onsite presence with the customer.
About Twoday
Twoday operates from modern offices across 30 locations in Norway, Sweden, Denmark, Finland, and Lithuania. We have a strong and unique social environment with highly engaged employees. If you are the candidate we are looking for, you will play a central role with exciting opportunities to grow within an international and innovative group, working on cutting-edge technology and software solutions. 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 all the requirements? Studies show that women and minorities are less likely to apply for a job if they don’t meet every qualification. At Twoday, we are committed to building a workplace and community where everyone is welcome. If you are excited about this role but your previous experience doesn’t perfectly align with the job description, we still encourage you to apply.