How do serverless systems handle streaming video and audio?

Serverless systems handle streaming video and audio by breaking the process into event-driven tasks and integrating with specialized cloud services. Instead of maintaining persistent servers, serverless functions (like AWS Lambda or Azure Functions) are triggered at specific stages of the streaming workflow. For example, when a user uploads a video, a serverless function might validate the file, generate metadata, or initiate transcoding using a dedicated service like AWS Elemental MediaConvert. The actual heavy processing, such as converting video formats for different devices, is offloaded to these purpose-built tools, while serverless acts as the glue that coordinates workflows. This approach avoids running resource-intensive tasks directly on ephemeral serverless compute, which has time and memory limits.

For delivery, serverless systems often rely on content delivery networks (CDNs) like CloudFront or Cloudflare, combined with edge computing. A serverless function at the edge (e.g., Lambda@Edge) can handle authentication, token generation, or geo-restriction checks before allowing access to the video stream. The media itself is stored in object storage (e.g., S3) or a streaming service like AWS MediaLive, which serves chunks via protocols like HLS or DASH. Serverless functions can also dynamically generate manifests or adapt stream quality based on real-time conditions, such as network bandwidth detected via client-side metrics. This decouples the stateless logic (handled by serverless) from the stateful, high-throughput streaming (handled by CDNs and media-specific services).

Real-time streaming scenarios, like live audio/video feeds, use hybrid architectures. Serverless functions manage signaling for WebRTC connections (e.g., negotiating peer-to-peer links) or process short audio/video segments. For example, a serverless function might analyze a 5-second audio clip for sentiment analysis using a third-party API, then store results in a database. Platforms like AWS Kinesis or Azure Event Grid can route streaming data chunks to serverless functions for near-real-time processing, such as moderation or transcription. However, the core media transport often relies on specialized protocols (RTMP, WebRTC) and services (Twilio, Agora) optimized for low latency, while serverless handles ancillary tasks like authentication, analytics, or triggering downstream workflows when specific events occur (e.g., detecting a keyword in a live stream).