Senior Software Engineer

About this role

ABOUT LUMILENS

At Lumilens we are building the critical photonics infrastructure that powers tomorrow’s AI supercomputing. From chip-to-chip optical interconnects to scalable photonic engines, Lumilens is unlocking a new era of computing faster, cooler, and massively more efficient.

We’re a well-funded startup backed by Mayfield and led by veterans who’ve built and scaled some of the most transformative technologies in the industry. This isn’t incremental innovation, it’s a ground-floor opportunity to rethink the optical layer from the silicon up. You’ll work alongside a team of world-class engineers solving some of the hardest challenges in optics, systems, and scale. Every line of code, every design decision, every breakthrough you help deliver will shape the infrastructure of tomorrow.

If you're looking for mission, momentum, and the chance to make an outsized impact—jump on the rocket ship. We’re just getting started ... and we are building a Team in Kraków!

What You Will Work On

• **C# / .NET desktop application** — Advanced manufacturing software for optical transceiver testing. A GUI application built with MVVM architecture, featuring multi-threaded test execution, instrument resource management, and RPC services.
• **Hardware integration** — Writing drivers and control code for laboratory equipment, managing parallel test execution and handling complex locking across instruments.
• **Python test scripts & libraries** – Our manufacturing software draws the best from both worlds. You will have the opportunity to integrate complex testing functionality based on Python code embedded natively into the .NET application.
• **Manufacturing scale** - You will be developing software that runs on manufacturing lines, producing thousands of units daily.

Required Skills:

• 5+ years of C#/.NET — experience with GUI (WPF or similar framework), MVVM, async/await, thread safety, and class library design
• Strong command of concurrent programming — designin...