PinEqualizer: Full Funnel Content Exploration and Debiasing System at Pinterest
For Pinterest, this system reduces bias favoring existing content and improves model accuracy across content types, with measurable short-term and long-term gains.
Pinterest addresses the cold-start problem in search and recommender systems with a full-funnel debiasing and exploration system, achieving significant improvements in fresh content exploration, user engagement, and ecosystem health.
In this paper, we propose a new solution for addressing the content cold-start problem in industry-scale search and recommender systems. Compared to prior approaches, we have made the following new contributions: 1) our solution spans the entire multi-stage funnel and generalizes well for both search and recommendation surfaces, 2) our solution reduces bias favoring existing content, allowing more accurate model prediction across content types and reducing short-term tradeoffs associated with high volumes of explicit content exploration, 3) our solution is evaluated with a scalable measurement framework that enables fast short-term experimentation while validating long-term impact. We have iteratively built and successfully deployed this new system at Pinterest in the past two years and observed significant improvements in fresh content exploration, overall user engagement, and content ecosystem health.