System Design: Banner Frequency Capping at 100M DAU — How Swiggy/Flipkart Show You Ads Exactly Twice a Day
Ever noticed how Swiggy shows you a promotional banner exactly twice before it disappears forever? That's not accidental — it's a carefully engineered frequency capping system running at massive scale. In this post I'll walk through how I designed this system to handle 100M daily users, 15K peak QPS, with sub-50ms latency using Redis, Kafka, and a rolling window quota engine.
Apr 27, 202612 min read77
