Senior Software Engineer

What if your next role let you shape the future of AI—and do it with empathy, responsibility, and real-world impact? One of the biggest challenges and opportunities with artificial intelligence is around the data used to train AI models, and how to do that responsibly and ethically whilst governing data protection, applying AI regulations, democratizing knowledge, and balancing individual rights with societal benefits.

As a Senior Backend Software Engineer in Project Hafnia, you will design, build, and maintain robust backend systems that power our data-driven AI services. While your primary focus will be test automation and quality engineering to ensure our software is reliable, maintainable, and scalable, you will also contribute to backend development. You will collaborate with DevOps, ML engineers, and QA specialists to implement efficient testing strategies, strengthen CI/CD pipelines, and support high-quality releases.

You will join our innovative and entrepreneurial development team at Milestone, a global leader in data-driven video management solutions. Our mission is to build a suite of services centered around a responsible data library, leveraging compliant, high-quality, ethically sourced video data. We follow a long-term strategy, continuously scrutinize emerging AI, and adhere to our ethical tech and responsible technology agenda.

 

Your owned perimeter:

As a Senior Backend Software Engineer, your responsibilities will include:

• Designing, implementing, and maintaining backend services, APIs, and data processing pipelines.
• Contributing to test automation frameworks, writing automated unit, integration, and system tests.
• Collaborating with ML engineers, DevOps, and QA to ensure software quality, scalability, and reliability.
• Troubleshooting production issues and participating in incident resolution and post-mortem analysis.
• Mentoring team members on best practices in software development, testing, and system design.

Where skill meets impact!

You might be the person we are looking for if you are a strong backend engineer who values high-quality code and has some experience or interest in test automation.

 

Dream Technical Skills:

• Container Strong backend programming skills (Python, Java, or similar languages).
• Experience with RESTful APIs, microservices, and distributed systems.
• Familiarity with databases (SQL and/or NoSQL) and data modeling.
• Experience with unit and integration testing; test automation knowledge is a plus.
• Comfortable working in CI/CD environments (Jenkins, GitHub Actions, GitLab CI/CD).
• Understanding of cloud-native architectures, containerization (Docker), and orchestration platforms (Kubernetes/OpenShift) is beneficial.
• Passion for writing clean, maintainable, and high-performance code.

 

Expected Experience or Equivalent:

• Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field.
• 5+ years of hands-on experience in backend software development.
• Experience designing and maintaining scalable, reliable, and maintainable systems.
• Exposure to automated testing practices is a plus.
• Familiarity with agile development workflows and cross-functional collaboration.

 

About project Hafnia and our team:

You will join about 25 fantastic colleagues in a fast-growing and broadly international team that besides the engineering core counts profiles across go-to-market, community, compliance, strategy and more. We operate as an autonomous product team and share an entrepreneurial mindset and a firm belief that we can cover new grounds to the benefit of the world. We work with trust, collaboration and flexibility as our foundations.

 

What else can Milestone offer you:

In addition to the exciting challenges of this role, Milestone provides:

• Opportunities for professional growth and development.
• A supportive company culture and inclusive workplace environment.
• Daily meals, snacks, and beverages in our canteen.
• Office amenities such as company bikes, a gym, massages, and Friday gatherings.
• Monthly company events for team bonding and enjoyment.

 

Location, application and contact:

Ideally, your base will be within regular travelling distance of our HQ in Copenhagen or our Madrid/Barcelona office but if you are the right profile, other options are possible.

We would like to receive your CV in English, avoid pictures; and cover letter won’t even be read. If you have any questions, you are very welcome to contact our Engineering Manager, Fulgencio Navarro (+34 662024273)

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