Senior .NET Backend Engineer for Payments Platform

Celsus Engineering AB; Denmark; Remote; DKK 900,000 - 1,200,000; Full time

Job summary

Celsus Engineering AB is building the next-generation payment platform on a modern tech stack. You will work in a cross-functional team to design, implement, and operate data-intensive services at scale.

Ideal candidates have strong .NET/C#, solid microservices and distributed systems skills, plus hands-on experience with Docker, Kubernetes/OpenShift, Kafka or similar messaging, and SQL Server. Proficiency in English is required; Swedish is a plus.

Qualifications

• Design, optimize, and operate data-intensive systems with MS SQL Server.
• Deep understanding of database performance, indexing, and query optimisation.
• Experience building backend services using .NET/C#, with microservice architectures and distributed systems.
• Experience designing asynchronous messaging and event-driven systems with Kafka/IBM MQ.
• Experience running services in containerised/orchestrated environments (Docker, Kubernetes/OpenShift) with scaling and resilience.
• Experience contributing to CI/CD pipelines for database changes and deployments with safe, repeatable releases.
• Collaborative engineering mindset, willingness to share knowledge and improve team practices.
• Meritorious with experience from financial services, payments, or regulated environments.
• Strong communication in English; Swedish is a plus.

Responsibilities

• Design, implement, and operate data-intensive systems for a modern payments platform.
• Collaborate with cross-functional teams to deliver reliable services at scale.
• Contribute to architecture decisions for microservices and event-driven components.

Skills

Data-intensive systems design

Schema design

Performance tuning

Production troubleshooting

English fluency

Regulated environments experience

Collaborative mindset

Tools

.NET/C#

Docker

Kubernetes/OpenShift

Kafka

IBM MQ

MS SQL Server

CI/CD for databases

Job description

Celsus Engineering AB is building the next-generation payment platform on a modern tech stack. You will work in a cross-functional team to design, implement, and operate data-intensive services at scale.

Ideal candidates have strong .NET/C#, solid microservices and distributed systems skills, plus hands-on experience with Docker, Kubernetes/OpenShift, Kafka or similar messaging, and SQL Server. Proficiency in English is required; Swedish is a plus.