Senior Java Developer

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.

Working at Twoday

Twoday is a leading technology consulting company specializing in applied AI and advanced engineering. With around 2,300 experts in AI, data, digital engineering, and cloud engineering, we cut through complexity, remove uncertainty, and prove the value of technology.

Our purpose is to create a better tomorrow through AI and technology. We strengthen private and public organizations across energy and utilities, financial services and insurance, industrials and manufacturing, health and life sciences, and government.

However, our greatest strength isn't the technology we work with. It's the people behind it. Every day, they bring together expertise, curiosity, and determination to help our customers solve complex challenges and create lasting value.

Diversity and inclusion

We are committed to building an inclusive and diverse workplace where everyone is treated with respect and has equal opportunities. Our recruitment decisions are based on competencies, experience, and individual merit.

Don’t meet all the requirements? Many candidates hesitate to apply unless they meet every qualification. We are looking for people who are engaged, meet most of the criteria, and are motivated to grow in the role. If this role interests you and you believe you could be a good fit, we encourage you to apply.