Senior Backend Architect, Online Payments Platform

Flatpay; Herlev Kommune; On-site; DKK 900,000 - 1,300,000; Full time

Benefits offered by this job

On-site gym

Gamer room on-site

Free slush ice

Job summary

Flatpay is building the online payments platform and seeks a Senior Software Engineer to define the technical direction and architecture for the online domain. You will help shape how the platform evolves as adoption grows and mentor engineers along the way.

You will design and implement scalable backend systems, APIs, and integrations, while collaborating with product teams to deliver high-impact payment experiences. Join our Copenhagen team and help Flatpay scale globally.

Qualifications

• 7+ 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.

Responsibilities

• Design and build scalable systems powering online payments and commerce experiences.
• Lead feature and platform initiatives involving multiple engineers, driving delivery from discovery through production.
• Take ownership of features from design and implementation through deployment and maintenance.
• Drive architectural decisions and long-term technical improvements.
• Build APIs, services, and integrations that enable online payment experiences.
• Improve reliability, observability, performance, and security across the platform.
• Partner with engineers, product managers, and stakeholders to drive technical and product outcomes.
• Mentor engineers through coaching, code reviews, and knowledge sharing.

Skills

7+ years experience

Distributed systems design

Lead technical projects

Backend APIs

Ambiguity navigation

Communication skills

Payments/fintech exposure

Tools

Docker

AWS

TypeScript

React

TanStack Query

Jest

Playwright

GitHub Actions

CI/CD

AWS ECS

Observability

Job description

Flatpay is building the online payments platform and seeks a Senior Software Engineer to define the technical direction and architecture for the online domain. You will help shape how the platform evolves as adoption grows and mentor engineers along the way.

You will design and implement scalable backend systems, APIs, and integrations, while collaborating with product teams to deliver high-impact payment experiences. Join our Copenhagen team and help Flatpay scale globally.