Senior .NET Backend Engineer
Celsus Engineering AB · 12 månader – upp till 2 år · Deadline 2026-12-01
Celsus Engineering AB is seeking a **Senior .NET Backend Engineer** to join a cross-functional team focused on building a next-generation payment platform using a modern tech stack. The position involves engineering backend services within microservice architectures and distributed systems, as well as handling asynchronous messaging and event-driven workflows with tools like Kafka or IBM MQ. Day-to-day responsibilities also include maintaining services in containerised environments like Docker and Kubernetes or OpenShift, alongside contributing to or owning CI/CD pipelines for deployment automation and database changes. Applicants must demonstrate solid experience building and running backend services with **.NET and C#**, as well as proven expertise in designing, tuning, and operating **MS SQL Server** environments for data-intensive systems. Strong communication skills and fluency in English are required. Experience working within financial services, payments, or other regulated environments is considered a plus, as is knowledge of Swedish.
Description
Build the next-generation payment platform on a modern and future-proof tech stack. Working in a cross-functional team
What we’re looking for
Proven ability to design, optimize, and operate data-intensive systems, including schema design, performance tuning, and production troubleshooting in MS SQL Server–based environments.
Deep understanding of database performance and reliability, including indexing strategies, query optimisation, and handling production issues.
Experience building and operating backend services using .NET/C#, with a solid understanding of microservice architectures and distributed systems.
Experience designing and working with asynchronous messaging and event-driven systems, using Kafka, IBM MQ, or similar technologies.
Experience running services in containerised and orchestrated environments (Docker, Kubernetes/OpenShift), with awareness of scaling, resilience, and failure modes.
Experience contributing to or owning CI/CD pipelines for database changes and deployment automation, with a focus on safe, repeatable releases.
A collaborative engineering mindset, with a willingness to share knowledge, learn continuously, and improve how the team builds and runs software.
Meritorious with experience from financial services, payments, or other regulated environments.
Strong communication skills, with fluency in English; Swedish is a plus