Backend Engineer (.NET) at Sent

Pristina, Kosovo · In-Office About Sent Sent is building the messaging infrastructure that powers how businesses communicate with their customers. We provide a unified API for SMS, WhatsApp, iMessage, and RCS, making it simple for developers to reach people on any channel. We've raised $5.8M in funding and we're growing fast. The Role We're looking for a Backend Engineer to build and maintain the core services that power Sent's messaging infrastructure. You'll work on the APIs, integrations, and backend systems that thousands of developers depend on to send millions of messages every day. What You'll Do • Build and maintain RESTful APIs. Design and ship the backend services that power Sent's multi-channel messaging platform. Write clean, well-tested code that's reliable at scale. • Own system reliability. Take responsibility for the uptime and performance of the services you build. When things break, you fix them. • Integrate across the stack. Connect Sent's platform to carrier networks, third-party providers, and internal services. Work with frontend and DevOps engineers to deliver end-to-end features. • Improve performance. Identify bottlenecks, optimize queries, and evolve database schemas as the product scales. • Contribute to architecture. Participate in technical design discussions and help shape how we build secure, scalable backend systems. What We're Looking For • 3+ years with C# / .NET / ASP.NET Core. You've built and shipped production backend services in this stack. You're comfortable with the ecosystem. • Strong RESTful API experience. You know how to design clean APIs, version them properly, and make them easy for developers to work with. • Solid database knowledge. You've worked with relational databases — designing schemas, writing efficient queries, thinking about data integrity. • Security and reliability mindset. You think about authentication, authorization, and failure modes when you write code — not after. • High-availability experience is a strong advantage. If you've built systems that need to stay up, that background will serve you well here. Why Sent We're a team building hard technical problems in messaging infrastructure. We value directness, craftsmanship, and actually shipping things. In Pristina, you'll be part of a close-knit engineering and operations team doing real work — not support work, not maintenance work. Work that matters. If you want to join a fast-moving company with a clear product and strong backing, this is that opportunity. Sent, Inc. is an Equal Opportunity Employer committed to building a diverse and inclusive team. We encourage applications from candidates of all backgrounds and experiences.