Figure 2: System architecture of the single fused GPU pipeline for Meta Andromeda. This pipeline co-locates index matching, fused scoring, and top-K selection on a single GPU server. The fused scoring kernel executes the entire per-user-ad computation — from embedding gathering to MoE interaction and scoring — in a single on-chip pass, keeping intermediate results in registers and shared memory to eliminate HBM bottlenecks. This co-design reduces network traffic by approximately 100x by sending only compact request payloads — surpassing 1 billion ads per second while scoring every eligible ad across Facebook and Instagram.