Design Problems/Ad Serving System

Ad Serving System

Hard
Real-time BiddingLow LatencyAuction

High-Level Architecture

Rendering diagram...

Design a computational advertising system that selects and serves targeted ads to users in real-time. The system runs real-time bidding (RTB) auctions, matches ads to user context, and optimizes for advertiser ROI while maintaining strict latency requirements. Think Google Ads or Facebook Ads.

Clarifying Questions

  • Scale? (10B ad impressions/day, 1M advertisers, 2B users)
  • Latency budget? (Total < 100ms from request to ad response)
  • Auction type? (Second-price auction with quality scoring)
  • Ad formats? (Display banners, native, video pre-roll)
  • Targeting capabilities? (Demographics, interests, retargeting, contextual)