Design ad frequency capping
Design Ad Frequency Capping System
Design a system for an advertising platform to implement frequency capping. The core requirement is to prevent users from seeing the same advertisement more than a configured number of times within a specified time window.
Examples of such caps include:
- A user sees a specific ad at most 3 times per day.
- A user sees ads from a particular campaign at most 10 times per week.
Your design should comprehensively address the following aspects:
Real-time Cap Checks
Detail how ad-serving systems will perform real-time checks against these caps before an ad is displayed to a user.
Impression Counting and Storage
Explain the mechanisms for counting and storing ad impressions.
Multiple Cap Scopes
Describe how the system will support various aggregation scopes, such as limits applied per user-ad, per user-campaign, or even at a household level.
Scalability and Performance
Address how the system will handle high Query Per Second (QPS) rates, maintain low latency for cap checks, and manage eventual consistency requirements across different geographical regions.
Data Integrity and Event Handling
Discuss strategies for dealing with impression counting data that may be delayed, duplicated, or arrive out of order.
Data Lifecycle Management
Outline approaches for data retention, the expiration of old counts, and the operational trade-offs between achieving high accuracy and maintaining low latency.
AI interview prep
Core dilemma
Balancing the need for extremely low-latency, high-QPS reads for real-time ad cap checks against the challenge of accurately and efficiently counting a massive, high-volume stream of impression events, often with eventual consistency requirements and complex aggregation scopes, across a globally distributed system.
3 tradeoffs and 3 stress tests locked
Interview prep
Unlock the interviewer X-Ray rubric, tradeoff matrix, stress tests, clarifying questions, and key concepts.
Design ad frequency capping
Design Ad Frequency Capping System
Design a system for an advertising platform to implement frequency capping. The core requirement is to prevent users from seeing the same advertisement more than a configured number of times within a specified time window.
Examples of such caps include:
- A user sees a specific ad at most 3 times per day.
- A user sees ads from a particular campaign at most 10 times per week.
Your design should comprehensively address the following aspects:
Real-time Cap Checks
Detail how ad-serving systems will perform real-time checks against these caps before an ad is displayed to a user.
Impression Counting and Storage
Explain the mechanisms for counting and storing ad impressions.
Multiple Cap Scopes
Describe how the system will support various aggregation scopes, such as limits applied per user-ad, per user-campaign, or even at a household level.
Scalability and Performance
Address how the system will handle high Query Per Second (QPS) rates, maintain low latency for cap checks, and manage eventual consistency requirements across different geographical regions.
Data Integrity and Event Handling
Discuss strategies for dealing with impression counting data that may be delayed, duplicated, or arrive out of order.
Data Lifecycle Management
Outline approaches for data retention, the expiration of old counts, and the operational trade-offs between achieving high accuracy and maintaining low latency.