Senior .NET Developer / Technical Lead

Expected, .NET, C#, SQL

Optional, Microsoft Azure

About the project, One of the largest logistics and storage companies in the region is looking for a Senior .NET Developer / Technical Lead to help build the next generation of its technology platform., , This is a hands-on role with significant ownership. You’ll work closely with the leadership and product teams, make important technical decisions, and help modernize a large operational platform used across the business., , Your first project, Your immediate priority will be building the backend APIs for a new customer mobile application., , Customers will use the app to manage their accounts and rentals, make payments, and access their storage units. You’ll work closely with the mobile team to design the APIs, authentication, permissions, integrations, and backend workflows that make this possible., , Beyond the mobile application, you’ll help move the business away from legacy systems and towards a modern, API-driven platform connecting customer applications, operations, payments, access control, reporting, notifications, and other core services.

Your responsibilities, Design and build production APIs and backend services using .NET / C#, Work closely with the mobile team on API contracts and backend workflows, Take ownership of key backend and architecture decisions, Integrate new services with existing systems and SQL databases, Help modernize and gradually replace legacy applications, Design secure and reliable integrations between business-critical systems, Improve testing, monitoring, documentation, and CI/CD practices, Help establish development standards as the platform grows, Mentor and potentially help build the future backend team

Strong commercial experience with .NET / C#, Proven experience building production backend systems and APIs, Strong understanding of API design, authentication, authorization, and security, Good SQL and database design experience, Experience integrating third-party or existing business systems, Experience working with or modernizing legacy applications, Understanding of cloud infrastructure, CI/CD, testing, and production support, Ability to take ownership and make sound technical decisions, Strong communication skills and a practical approach to solving problems

Optional, Azure or another major cloud platform, Payments, Mobile application backends, Access-control, IoT, or hardware-connected systems, CRM, ERP, CMS, or operational platforms, Umbraco, Microservices or event-driven systems, Leading or mentoring other developers

What we offer, $5,000-$5,500/month (B2B Contract), + Relocation bonus for candidates moving to Warsaw, + Rewarding Milestone bonuses for product deliveries, OnSite New Modern office in Warsaw, Direct access to the CEO, Fast-moving environment with minimal bureaucracy, Long-term career growth as the engineering team expands

Why join?, This isn’t a maintenance role., , You’ll have the opportunity to influence the architecture of a major new platform, replace legacy technology with modern systems, and see the software you build used directly by customers and operations., , You’ll join at an important stage of the project with the opportunity to take real technical, ownership and grow into a broader leadership role as the engineering team expands.