Video Streaming - Netflix Expertise

Expert: Marcus Johnson (Netflix, 14 years) Level: 10/10 - Netflix Principal Engineer

Overview

Video streaming at Netflix scale - 260M+ subscribers, petabytes of video served daily, 99.999% uptime. The playbook that powers the world's largest streaming service.

Netflix didn't just build a streaming service - they revolutionized how video is delivered globally.

When to Use What

Video Encoding:

• H.264 (AVC) - Universal compatibility - H.265 (HEVC) - 50% better compression
• AV1 - Next-gen, 30% better than HEVC

Streaming Protocols:

• HLS - Apple devices, iOS/Safari - DASH - Android, web browsers
• CMAF - Unified format for both

CDN Strategy:

• Multi-CDN - AWS CloudFront, Akamai, Fastly - Open Connect - Netflix's own CDN

Quality Metrics:

• VMAF - Video quality scoring

Core Workflow

1. Ingest - Upload source video (high quality)
2. Encode - Multi-bitrate ladder (4K → 240p)
3. Package - HLS/DASH manifests
4. Distribute - Upload to CDN/S3
5. Stream - Adaptive bitrate playback
6. Monitor - Quality metrics, rebuffer rate

Netflix's Encoding Pipeline

Per-Title Encoding:

• Analyze each title's complexity
• Optimize bitrate ladder per video
• Save bandwidth without quality loss

Example: Simple animation needs less bitrate than action movie.

Adaptive Bitrate Streaming (ABR)

Client automatically switches quality based on network:

Network fast → 4K (16 Mbps)
Network medium → 1080p (5 Mbps)
Network slow → 480p (1 Mbps)

Netflix's Global Scale

• 260M+ subscribers worldwide
• Billions of hours streamed monthly
• 15,000+ video titles (each in 10+ bitrates)
• Petabytes served daily
• 99.999% uptime (5 minutes/year downtime)

CDN Strategy

Netflix uses:

1. Open Connect - Own CDN, 95% of traffic
2. AWS CloudFront - Backup/overflow
3. Edge caching - Videos cached near users

Best Practices

1. Per-title encoding - Optimize bitrate per video
2. VMAF quality scoring - Measure perceptual quality
3. Multi-CDN - Redundancy and performance
4. Adaptive bitrate - Smooth playback on varying networks
5. Edge caching - Reduce latency globally

Related Skills

• aws-expert - S3, CloudFront CDN
• microservices - Netflix architecture
• performance-optimization - Video player optimization

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Last Updated: 2026-02-03 Expert: Marcus Johnson (Netflix, 14 years) - Streams to 260M+ users