DoorDash redesigns explore page Feed Service with a DAG-based pipeline pattern, achieving 35% latency reduction and 60% CPU reduction
DoorDash's explore page Feed Service made repeated, duplicative calls to downstream services for every carousel, could rank only within a single carousel rather than across the page, and lacked modularization — causing development overhead to grow proportionally with system complexity as the business scaled.
The new pipeline achieved a 35% p95 latency reduction for the explore feed endpoint, a 60% CPU reduction from the Feed Service, an 80% QPS reduction and 50% CPU reduction from the Search Service, and an overall estimated reduction of 4,500 CPU cores, while enabling cross-carousel ranking and extending the pattern to new applications.
The previous Feed Service architecture made duplicative downstream calls per carousel, constrained ranking to the Search Service where it could only operate within individual carousels, and required candidate generation logic to be duplicated across multiple applications with strongly overlapping functionality.