Streaming from serverless Node.js and Edge Runtime on Vercel

What this post added

This post details Vercel's custom solution for enabling HTTP response streaming on AWS Lambda, which lacks native support. It explains the request flow through the Edge Location and Serverless Function Invocation Service, the modification of requests with callback URLs, and the use of a bridge code within Lambda to establish a secure socket connection for transferring the response stream back to the invocation service for client delivery. This significantly reduces TTFB and FCP by allowing incremental data processing.