About the projectYou will lead the technical development of a new backend platform serving as the operational core of a nationwide logistics ecosystem. The system will manage complex business logic, large-scale integrations, and communication between multiple systems and applications. As Senior .NET Developer, you’ll play a key role in architecture decisions, performance optimization, and mentoring the development team.Project duration: approx. 12 months with the possibility of extension.Please note: After the first three months of cooperation, participation in a standby/on-call rotation (including 24/7 availability) will be required.Tasks Define and lead the backend system architecture to ensure scalability, reliability, and maintainability Build and optimize RESTful APIs using .NET 8 and ASP.NET Core Design and implement complex business logic following DDD principles Oversee integrations with enterprise systems (REST/SOAP, SAP/WMS, authorization services) Collaborate on infrastructure setup and DevOps pipelines (Docker, RabbitMQ, Redis) Ensure system performance and resilience across thousands of concurrent users Conduct code reviews and provide technical mentorship to junior and mid-level developers Work closely with the product and operations teams to deliver high-quality, production-ready solutions Must have 5+ years of professional experience in .NET backend development Strong command of C#, ASP.NET Core, and REST API architecture Proven experience designing system architecture and database-based solutions Advanced knowledge of SQL Server, Entity Framework Core, Docker, and microservices design Familiarity with caching (Redis), messaging systems (RabbitMQ), and CI/CD pipelines Strong grasp of coding frameworks (xUnit), and clean code principles Excellent analytical thinking, communication, and leadership skills Polish language proficiency at C1 level, English at B2+ Nice to have Experience with GCP/AWS, Terraform, and monitoring tools (NewRelic, DataDog) Awareness of API security and cloud best practices Experience in AI-powered code completion and assistance tools such as GitHub Copilot and Tabnine Proficiency in modern AI-enhanced IDEs, including JetBrains IDEs, CLion, and Fleet Familiarity with AI-assisted test generation and debugging tools, such as Qoda What do we offer? ambitious, creative, talented & highly experienced team contributing to projects for clients all over the world flexible working hours and a possibility to work remotely We value your trust in providing us your data, thus we are striving to use commercially acceptable means of protecting it. Below you will find the necessary information about the data we collect and process when you send us your CV.The controller of your personal data is Miquido Spółka z ograniczoną odpowiedzialnością sp. k. with its seat in Krakow, Zabłocie 43a, 30-701 Kraków, Poland (“Miquido”, “We”, “Our” or “Us”). See more