A HoloLens developer creates and optimizes applications for Microsoft's HoloLens, a mixed reality smartglasses product. They utilize programming languages like C# and development tools such as and Visual Studio to create interactive holograms. They integrate APIs and data sources to provide real-time information within the holographic environment. Their work involves designing user interfaces, troubleshooting, debugging, and ensuring seamless performance on the HoloLens device. They also collaborate with UX/UI designers, testers and other stakeholders to develop user-centric applications, often in industries like gaming, education, healthcare, and manufacturing. They continuously update their skills to keep up with evolving AR/VR technologies.