System Developer for Major Client

System Developer – Senior Level 4 Location: Sundbyberg (SE) • Remote Work: Up to 50% Assignment Period: February 1, 2026 – February 1, 2028 Application Deadline: November 26, 2025 About the Assignment We are seeking a senior System Developer for one of the country's most significant authorities in energy and critical societal infrastructures. Here, you will work in an environment where technology is central to meeting future demands for energy systems, stability, and sustainability. You will be part of a long-term assignment where you will develop and manage systems that are crucial for Sweden's entire electricity market. The projects are conducted in an agile manner, often in sprints, and you will work closely with development teams, architects, and the business. Your Responsibilities As a system developer, you will contribute to both maintenance and development projects. The work may take place in smaller or larger teams and may also include aspects of requirements work, UX, or testing in some cases. You will, among other tasks: • Design, implement, and test system solutions • Develop and further enhance web applications and services • Manage incidents, perform troubleshooting, and bug fixing • Contribute to requirements and system documentation • Collaborate with other development teams and stakeholders within the organization • Work with high demands on IT security and robust system solutions An interest in system architecture and IT security is advantageous. Technology Stack & Competencies You should have solid experience in: • C# / .NET Core • REST API • ASP.NET • Entity Framework Core • MS SQL • HTML, CSS, JavaScript • System development in complex environments • Swedish at an expert level Additional Information • Scope: 100% • Location: Sundbyberg (remote up to 50%) • Start: February 1, 2026 • End: February 1, 2028 • Option: 1 + 1 year (possible extension until February 1, 2030) • The assignment will be carried out as a resource consultant and led by the client's organization • Security clearance will be necessary for the assignment • The consultant may work on multiple projects within the same role and scope Apply Now! Interviews are conducted on an ongoing basis, and the position may be filled before the deadline. We welcome your application!