My first year on Horizon Worlds was spent building profiling tools for creators who need ways to optimize and debug their worlds and games.
When the Meta Horizon Engine came out, I switched over to developer platform engineering, creating the scripting platform for creators and enormous system tools needed to make that happen. The Meta Horizon Engine is a proprietary engine by Meta built from the ground up to support massive multiplayer concurrent operations and the creator-facing tools allowing them to create custom experiences.