Penny Xu

About Me

I'm a systems engineer in the Bay Area. I work on GPU and graphics systems at Apple — screen capture, display pipelines, the layer where software finally meets the hardware — and before that, the Vulkan driver stack at Samsung. Computer Engineering at UIUC, with a semester at EPFL.

What I enjoy most is making things fast on real hardware: how a workload maps onto a GPU, where the memory and time actually go, and what it takes to run vision and ML models efficiently on-device. Lately that has included a detour into how large language models get served, which turns out to be an operating systems problem wearing a machine learning hat.

I write here to understand things properly. If an idea won't fit in my head, I draw it until it does.

Outside of that: tennis, skiing, motorcycles. Also challenge me in chess!

Penny Xu