Personalized Recommendation of Dish and Restaurant Collections on iFood

TL;DR

This paper introduces RED, a personalized recommendation system for curated food collections on iFood, utilizing machine learning and content-based methods to improve user engagement and overcome cold-start and bias challenges.

Contribution

The paper presents a novel large-scale recommendation system for curated food collections, integrating content-based representations and bias mitigation techniques for the first time in a commercial setting.

Findings

97% improvement in Card Conversion Rate

1.4% increase in overall App Conversion Rate

Offline metrics strongly correlate with online performance

Abstract

Food delivery platforms face the challenge of helping users navigate vast catalogs of restaurants and dishes to find meals they truly enjoy. This paper presents RED, an automated recommendation system designed for iFood, Latin America's largest on-demand food delivery platform, to personalize the selection of curated food collections displayed to millions of users. Our approach employs a LightGBM classifier that scores collections based on three feature groups: collection characteristics, user-collection similarity, and contextual information. To address the cold-start problem of recommending newly created collections, we develop content-based representations using item embeddings and implement monotonicity constraints to improve generalization. We tackle data scarcity by bootstrapping from category carousel interactions and address visibility bias through unbiased sampling of impressions and purchases in production. The system demonstrates significant real-world impact through extensive A/B testing with 5-10% of iFood's user base. Online results of our A/B tests add up to 97% improvement in Card Conversion Rate and 1.4% increase in overall App Conversion Rate compared to popularity-based baselines. Notably, our offline accuracy metrics strongly correlate with online performance, enabling reliable impact prediction before deployment. To our knowledge, this is the first work to detail large-scale recommendation of curated food collections in a dynamic commercial environment.