Meta Quest has now reached tens of millions of users and made over a billion dollars, but the technical challenges remain immense, with a wearable form factor and a power-constrained mobile SoC. David gives an overview of the Quest build and optimize flow, geared towards console and PC developers, with an eye toward graphically-demanding, immersive games. Mixed reality enables new creative possibilities, but it puts unique demands on programmers, artists, and designers. We share the lessons of a ten-year journey from developer kits to Quest 3.