When a client requests 3D graphics, Steven often has to explain that he can do it, but it will take weeks, or months, and no one in-house will be able to maintain it. This led to the creation of Use.GPU, a Typescript library that drives WebGPU. Use.GPU capitalizes on familiar web patterns like JSX and evolves them, sometimes quite remarkably, to establish a declarative and reactive programming model. This is realized with Live, a React-like runtime that employs a memoized effect system. The entire program is constructed as if 1 frame is all that's needed. Then, to become interactive and animate, it selectively rewinds and reruns parts of itself. It's unusual, but it works. This talk will explain how it works, how it relates to classic effect systems, and the insights gained while building it.