Software Engineer, Online Payments Platform

Flatpay; Herlev Kommune; On-site; DKK 700,000 - 900,000; Full time

Benefits offered by this job

free slush ice

on-site gym

gamer room

much more

Job summary

Flatpay is building online payments platforms from the ground up in Copenhagen. As a Software Engineer, you will design, develop, and launch new products, contribute to architectural decisions, and scale solutions as adoption grows across markets.

You’ll own features end-to-end, collaborate with product managers and designers, and work across backend, frontend, and platform delivery using Java, TypeScript, AWS, and modern tooling. A growth mindset and customer-focused impact are valued.

Qualifications

• 3–6 years of professional software engineering experience.
• Experience building and operating production systems.
• Comfortable working across modern backend and cloud technologies.
• Strong understanding of software engineering fundamentals.
• Curious, pragmatic, and eager to learn.
• Enjoy taking ownership and solving real customer problems.
• Experience with payments, e-commerce, SaaS platforms, or fintech is a plus.

Responsibilities

• Design, develop, and maintain software solutions for online commerce and payments.
• Build new merchant- and customer-facing features, APIs, and services.
• Take ownership of features from design and implementation through deployment and maintenance.
• Improve the reliability, scalability, and performance of existing systems.
• Collaborate with product managers and designers to deliver customer value.
• Participate in technical discussions, code reviews, and architecture decisions.
• Contribute to testing, deployment, and operational excellence.
• Work closely with other engineering teams across Flatpay to build integrated solutions.
• Help improve engineering practices, tooling, and development workflows.

Skills

Software engineering

Production systems

Cloud technologies

Ownership

Curious & eager to learn

Payments/fintech experience a plus

Tools

Java

Spring Boot

MySQL

REST APIs

Event-Driven Architecture

Domain Driven Design

Docker

AWS

TypeScript

React

TanStack Query

Jest

Playwright

i18n

feature flags

GitHub Actions

CI/CD

AWS ECS

Observability

Job description

Flatpay is building online payments platforms from the ground up in Copenhagen. As a Software Engineer, you will design, develop, and launch new products, contribute to architectural decisions, and scale solutions as adoption grows across markets.

You’ll own features end-to-end, collaborate with product managers and designers, and work across backend, frontend, and platform delivery using Java, TypeScript, AWS, and modern tooling. A growth mindset and customer-focused impact are valued.