Senior Backend Engineer - Payments, Cloud & AI-Driven

ApplyMint; Denmark; On-site; DKK 900,000 - 1,200,000; Full time

Benefits offered by this job

Flexible Work Environment

Competitive package with pension

32 paid vacation days and parental-lea

Career Growth

Coffee, snacks, and office perks

Job summary

Spirii is seeking a Senior Backend Software Engineer to join the Payments team in Copenhagen, Denmark. You will own scalable backend services, cloud-native pipelines, and data processing for invoices, credit memos, and payouts.

You will mentor engineers, shape architecture for distributed systems on AWS, and advocate for robust testing, observability, and AI-assisted development in a financially sensitive codebase.

Qualifications

• Bachelor's degree in CS or equivalent.
• 7+ years of professional software development experience.
• Experience designing and scaling production backend systems and event-driven architectures.
• Strong TypeScript/JavaScript (Node.js, NestJS) on AWS.
• Leadership: design discussions, mentoring engineers, or tech lead role.
• Hands-on with TDD, test automation, integration and load testing.
• Strong SQL and data modeling for auditable, accurate data.
• ERP integration and billing/payments experience is a plus.

Responsibilities

• Design, build, and maintain scalable backend services and cloud-native pipelines.
• Ensure data quality and safe handling of late or updated records.
• Integrate with internal services and our ERP system.
• Contribute to architecture for cloud-native, distributed systems on AWS.
• Drive automated testing and observability for billing correctness.
• Mentor engineers and raise the technical bar via code reviews.
• Operate independently on cross-team problems with minimal oversight.
• Leverage AI coding assistants and agentic workflows to accelerate development.

Skills

Node.js

TypeScript

NestJS

AWS

SQL

Data modeling

Mentoring

Education

Bachelor's degree in Computer Science, Software Engineering, or related field

Tools

Redis

NoSQL databases

ERP systems integration

APIs

Event-driven architectures

Job description

Spirii is seeking a Senior Backend Software Engineer to join the Payments team in Copenhagen, Denmark. You will own scalable backend services, cloud-native pipelines, and data processing for invoices, credit memos, and payouts.

You will mentor engineers, shape architecture for distributed systems on AWS, and advocate for robust testing, observability, and AI-assisted development in a financially sensitive codebase.