Full Stack Product Engineer – Fintech (AI-first, high ownership)

Do you want to build a real fintech platform used by businesses every day - and help redefine how a small, high-performing team builds with AI?

Flex Funding is a Scandinavian crowdlending platform helping SMEs access flexible financing across Denmark and Norway, backed by 4,000+ investors. We are expanding into Sweden and building new financing products - while evolving how we design, build, and scale our platform.

We are now looking for another strong full stack engineer to join a small, highly capable team; someone who takes ownership, moves fast, and actively improves both product and engineering practices.

The role

This is not a “ticket-driven” role.

You will work in a small team with one other full stack developer and external DevOps support. That means broad responsibility, real ownership, and direct impact on both product and technical direction.

You will:

• Build end-to-end solutions: from idea and prototype to production-ready systems used by real customers.

• Improve how we build: introduce and operationalize AI across coding, testing, documentation, and refactoring.

• Reduce complexity: simplify existing systems and make it faster and safer to ship new features.

• Work closely with business, compliance, and partners in a regulated environment.

This is a startup-style environment inside an established fintech: high autonomy, fast decisions, and visible impact.

Current tech

• Backend: C#, ASP.NET Core, REST / GraphQL, Azure SQL

• Architecture: modular, API-driven, secure financial workflows

• Frontend: Vue / Nuxt

• Infrastructure: Azure, CI/CD pipelines

What we’re looking for

We are looking for someone who builds, takes responsibility, and gets things done.

You likely:

• Have 5+ years building and shipping full stack systems in production

• Take ownership beyond code - you care about whether the solution actually works in practice

• Are proactive: you don’t wait for perfect specs, you move things forward and solve problems

• Think in systems and data: architecture, trade-offs, and long-term maintainability

• Use AI tools actively in development and want to push this further in a real production environment

• Can challenge existing solutions and suggest pragmatic improvements

• Communicate clearly with both technical and non-technical stakeholders

It’s a strong plus if you have

• Experience in fintech, lending, payments, or regulated environments

• Worked with APIs and third-party integrations

• Experience improving or modernising existing systems

• Built products in smaller teams or startup environments

Language

• Danish is required for this role (due to collaboration and regulatory context)

Why join Flex Funding

• A live platform creating real value for businesses every day

• A small, experienced team with high trust and low bureaucracy

• Real ownership and influence on architecture, product, and AI adoption

• The opportunity to both build new and improve what already works

• A growing fintech expanding across the Nordics

Practical

• Full-time

• Location: Copenhagen (CPH Fintech Lab)

• Start: as soon as possible

Apply

Send your CV and a short motivation to: gunvor.overbye@flexfunding.com

We review applications on an ongoing basis.