Senior Software Engineer – (Configuration and programming language design)

Join Us in Challenging the Life & Pension Sector.

Do you love programming language design, sophisticated verification logic and engineering solutions from start to finish? Festina Finance is looking for a Senior Software Engineer to evolve our configuration solutions, enabling business specialists to define and change the behaviour of the Festina Life and Pension platform.

Our Life & Pension solutions power the biggest pension funds in Denmark and the Netherlands and more than 30 banks across Scandinavia and the UK. As part of our fast‑growing and ambitious organization, you will help shape the core of systems used across Europe while working in a flat, informal culture with plenty of autonomy and room to influence.

What You Will Join

Festina Finance builds modern, high‑performance software platforms for the financial sector. You will join a team of highly skilled developers, actuaries, and domain specialists who work closely together to deliver solutions that are both technically strong and deeply rooted in business logic.

We value craftsmanship, curiosity, and collaboration. You will experience a workplace where people take responsibility, share knowledge, and enjoy solving hard problems together while having fun as a team.

Why this role is exciting

This role gives you the opportunity to work with a highly specialized and industry‑defining product that pushes the boundaries of what is possible in the pension sector. You will operate close to the core of our platform, where programming language design, verification and advanced business logic meet modern software engineering.

The products you will design are at the basis of all calculations and provide the definition of the business in the Festina Life and Pension platform. Scalability, performance, and proper design are key. Here you will get to work in the intersection between programing language design, systems architecture and direct contact with the people who depend on the result. You can expect your solutions to be in use for many years to come.

We produce solutions as a team and frequently have whiteboard sessions discussing upcoming designs and development changes. You can expect to learn through a mixture of individual work and team-based iteration.

What you will work on

Your work will span four main areas:

• Language, semantics and verification: Extend the syntax and semantics of F+, our own in-house functional programming language for financial domains. Design and strengthen the verification logic that ensures configuration is correct before it ever reaches production.
• Systems and architecture: Evolve our purpose-built version control system for F+. You will work with database design, API design, caching strategies, concurrency models, and performance.
• Tooling and operations: Build the configuration tools our business specialists rely on, including applications and integrations, and maintain the CI pipelines and production environment behind them — including monitoring and continuous cluster operations.
• Domain and customers: Analyze business domains, translate them into working solutions, and handle complex customer issues through direct contact with the people using what you build.

Needed skills

To thrive in this role, you should bring strong engineering fundamentals and a mindset suited for mission‑critical systems:

• Strong software engineering fundamentals
• A verification-driven mindset you enjoy building robust validation and verification
• Ability to take an idea from design to implementation while owning responsibility
• Experience designing large‑scale solutions for customers with active production systems
• A highly critical and detail‑oriented mindset our solutions sit at the core of all product calculations
• Strong collaboration skills we communicate intensively when exploring new design spaces
• A master’s degree in computer science or equivalent experience