Yelp Engineering and Product

Samuele Mazzanti, Applied Scientist

February 2, 2026

Introduction Modern advertising platforms are fast-paced and interconnected: even small adjustments can have ripple effects on how ads are shown, how budgets are spent, and the value advertisers get from their ad spend. At Yelp, Ad Budget Allocation means splitting each campaign’s spend between on‑platform inventory (our website, mobile site, and app) and off‑platform inventory (the Yelp Ad Network). We optimize this split to meet advertisers’ performance goals while growing overall revenue. Due to the complexity of the budget allocation system and its feedback loop, even small changes can lead to unexpected system‑wide effects. To help us safely evaluate changes,...

Nurdan Almazbekov, Infrastructure Security

September 26, 2025

Introduction Yelp heavily relies on Amazon S3 (Simple Storage Service) to store a wide variety of data, from images, logs, database backups, and more. Since data is stored on the cloud, we need to carefully manage how this data is accessed, secured, and eventually deleted—both to control costs and uphold high standards of security and compliance. One of the core challenges in managing S3 buckets is gaining visibility into who is accessing your data (known as S3 objects), how frequently, and for what purpose. Without robust logging, it’s difficult to troubleshoot access issues, respond to security incidents, and ensure we...