Text Behind Image : an editor where you upload a photo, the background gets removed using an ML model, and then you place stylized text between the foreground subject and the background. The text appears to sit behind the person or object in the image.

There's no way to express this UI in Gradio components. It's a full web application. But We still wanted the backend power of Gradio: queuing, concurrency management, ZeroGPU support, and hosting on HF Spaces without infrastructure headaches.

gradio.Server extends FastAPI. It gives you the full power of FastAPI (custom routes, middleware, file uploads, any response type) while adding Gradio's API engine on top: queuing, SSE streaming, concurrency control, and gradio_client compatibility.

That's it. ~50 lines of Python. The model loads at startup, @spaces.GPU handles ZeroGPU allocation, and gradio.Server manages queuing and concurrency. Let's break down what's happening.