Design real-time ad impression and spend tracking

Company: Snapchat

Role: Software Engineer

Category: System Design

Difficulty: medium

Interview Round: Onsite

Quick Answer: This question evaluates system design and distributed systems skills, focusing on real-time event ingestion, accurate counter aggregation, low-latency read paths, scalability, and consistency in an ad impression and spend-tracking context, and it belongs to the System Design/backend domain.