How Netflix Built a Distributed Counter for Billions of User Interactions

Netflix developed a Distributed Counter Abstraction to handle billions of user interactions globally, ensuring low latency, high throughput, and cost efficiency. The system supports two types of counting:

• Best-Effort Counting: Provides approximate, fast results.
• Eventually Consistent Counting: Ensures accurate, durable metrics.

Netflix's hybrid approach combines event logging, background aggregation, and caching to balance speed, accuracy, and scalability, enabling real-time decision-making and infrastructure optimization.

Core Technical Concepts/Technologies

• Distributed Counter Abstraction
• Best-Effort Counting vs. Eventually Consistent Counting
• EVCache (Netflix's distributed caching solution)
• Apache Kafka (durable queuing system)
• Cassandra (durable storage for counters)
• TimeSeries Abstraction (for temporal data management)
• Rollup Pipeline (background aggregation process)