SeniorPrincipal.NETDeveloper

_We are seeking a Senior Principal Developer with strong technical expertise and a drive to shape modern, scalable systems. This is an opportunity to work at the centre of Saxo’s platform, where your decisions will directly influence reliability, performance, and long-term architecture._ The Back Office Core team builds the foundation of our post-trading systems. Every line of code and every system architecture we create ensures trust, drives efficiency, and secures the accurate financial state of our platform. We are, in many ways, the heartbeat of post-trading operating at the core of a global, revenue-critical environment. You will collaborate closely with senior post-trading developers across locations and play a key role in mentoring engineers, influencing engineering standards, and guiding architectural direction. Based in our Copenhagen headquarters, you will also work in a global setup alongside our engineering teams in India. _At Saxo, you will not just build systems you will help define how we evolve them._ **Responsibilities** In this role, you will take ownership of both building and evolving critical systems, working hands-on while contributing to long-term architectural direction. Your responsibilities will include: * Building scalable, high-performance solutions using C#/.NET and .NET Core * Designing and maintaining RESTful and gRPC APIs with clear, business-aligned contracts * Working across event-driven and service-oriented architectures in a distributed environment * Maintaining and optimising SQL Server databases, including performance-critical and legacy DB-centric components * Driving the modernisation of legacy systems, transitioning towards loosely coupled, scalable architectures * Ensuring high standards of reliability, correctness, observability, and performance in revenue-critical systems * Contributing to architecture decisions, engineering standards, and platform evolution * Facilitating entity-based communication using Kafka * Taking ow