What will you do? As a Staff .NET Developer at Rebtel you will serve as the technical guardian and principal individual contributor for the entire Backend (BE) architecture and ecosystem. This role is crucial for ensuring the technical excellence, scalability, reliability, and security of all backend systems that power our core products and services. The Staff Software Engineer will operate at a high level of abstraction, influencing engineering practices across multiple teams while remaining hands-on in critical areas. You’ll be actively involved in architectural decisions, contribute to technical discussions, and inspire your team to deliver clean, robust code. Responsibilities and Tasks: Lead the design, development, and deployment of complex, high-throughput backend services and APIs, ensuring best-in-class performance and maintainability. Drive architectural decisions and serve as the ultimate technical escalation point for BE-related challenges. Establish and articulate a clear, ambitious long-term vision and technical roadmap for the evolution of the BE systems. This includes planning for future growth, anticipating technological shifts, and driving the adoption of new technologies and patterns to maintain a competitive edge. Act as the primary architect for major system initiatives, defining microservices boundaries, data models, integration patterns, and deployment strategies. Proactively identify and resolve technical debt and architectural risks before they impact the business. Mentor engineers, elevating the technical expertise and quality of engineering output across the organization. Influence engineering standards and best practices for testing, performance tuning, and security across different development teams. Requirements: Exceptional and proven proficiency in the .NET area, including extensive experience with C#, .NET Core/8+, and related frameworks (e.g., ASP. NET Core, Entity Framework Core). Must demonstrate the ability to architect and build high-performance, fault-tolerant systems using the .NET stack. Demonstrable architecting skills with a strong background in designing and implementing large-scale, distributed systems (e.g., microservices, event-driven architectures, serverless). Expert knowledge of design patterns, domain-driven design (DDD), and SOLID principles. Extensive experience with at least one major cloud platform (AWS, Azure, or GCP) and related services (e.g., managed databases, message queues, containerization). Deep understanding of various database technologies (SQL and NoSQL) and data modeling best practices for scalable applications. System-Level Thinking: Ability to decompose complex problems into manageable components and evaluate trade-offs between different technical solutions (e.g., speed vs. stability, buy vs. build). Excellent verbal and written communication skills, with the ability to present complex technical ideas clearly to both technical and non-technical stakeholders, driving consensus on critical architectural decisions. Why Rebtel? Rebtel has been connecting people across borders for nearly 20 years. Today, we’re profitable, growing, and at a pivotal moment in our journey. As we enter our next phase, we’re building an organisation designed for speed, ownership, and real impact, where every role contributes directly to shaping what comes next. This is a place with global ambition and a strong foundation, where ideas move quickly and decisions matter. You won’t get lost in layers of process or slow-moving structures. Instead, you’ll find the space to take ownership, collaborate across teams, and make meaningful contributions from day one. Based in Stockholm, we bring together a diverse, international team united by a shared purpose: to simplify the way people connect worldwide. At Rebtel, you are the most important asset and we strive to provide a comprehensive package of benefits and perks that enhance your well-being and work experience. Here are some of the things you can expect from us: Pension Plan Health Checkups, Influenza shots and Private Medical Insurance Dental Insurance Occupational insurance Wellness allowance (5,000 SEK) Discount on gym memberships Bonus program Extra parental pay 30 days annual vacation Monday breakfasts Relocation Support, if you're joining us from afar, we'll assist you in making a smooth transition. We are Rebtel. We come from all around the world to create products for anyone who has crossed a border. We believe in equal opportunity and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.