Senior software Engineer, Internal tools

About the job

You’ll be joining a high-performing and rapidly expanding team of engineers at one of Denmark’s fastest-growing companies. Together, we’re building and scaling the internal platforms that power our growth—including CRM system, sales tools, and operational software used daily and enabling our commercial organization to operate efficiently at scale as we continue our European expansion.

This is an opportunity to be part of a company that has grown from startup to unicorn at record speed. As we continue to into new markets and serve an ever-growing customer base, you’ll work on challenges that come with operating products at scale. You’ll have significant ownership, the freedom to drive technical decisions, and a direct impact on the solutions used by businesses every day. As we grow, so will your opportunities to develop your skills, take on new responsibilities, and help shape the future of commerce across Europe.

What you'll do

Design and deliver scalable, maintainable, and high-quality solutions that drive business impact

Enhance and evolve core internal systems to improve reliability, performance, and user experience

Continuously optimize CI/CD pipelines and infrastructure to accelerate delivery and increase stability

Collaborate closely with internal stakeholders to shape ideas, define requirements, and turn them into actionable plans

Lead cross-functional projects from concept to successful delivery

Mentor and support team members, fostering technical growth and engineering excellence

Drive architectural improvements and champion best practices to ensure the platform scales for the future

Who you are

5+ years of professional software engineering experience

Strong experience designing and operating distributed systems

Demonstrated ability to lead technical projects involving multiple engineers and influence architectural decisions

Experience building scalable backend platforms and APIs

Comfortable navigating ambiguity with pragmatism and helping shape new products and systems

Strong communication and collaboration skills

We don't expect experience with every technology listed below. We're looking for engineers who can learn quickly and help us build great products.

Backend

Java, Spring Boot

MySQL

REST APIs & Event-Driven Architecture

Domain Driven Design

Docker, AWS

Frontend

TypeScript

React

TanStack Query

Jest

Playwright

i18n

Platform & Delivery

GitHub Actions

CI/CD

AWS ECS

Observability & Monitoring

Feature flags

Why Flatpay?

You’ll help build and scale our internal platform, creating tools that empower teams across Flatpay and shape the future of how we operate, and scale our products.

We offer an inclusive environment where engineers are trusted with ownership and encouraged to make an impact. Our engineering teams work together from our Copenhagen office. We believe that close collaboration, quick feedback loops, and solving problems side-by-side help us build better products, move faster, and create a stronger engineering culture. We also provide plenty of perks including free slush ice, an on-site gym, a fully equipped gamer room, and much more. If you are ready to be part of this exciting journey, we would love to hear from you today.