How to Build Multi-CDN HLS Failover Using Content Steering and a 40-Line Server

A developer tutorial published on DEV Community demonstrates how to implement multi-CDN failover for HLS video streams using the HLS Content Steering specification, hls.js, and a minimal Express server. The approach avoids traditional client-side URL-rewriting hacks, which typically cause buffer loss and stream resets when switching CDNs. Instead, routing decisions are handled at the manifest layer by a small Node.js steering server that returns a JSON document specifying CDN pathway priority. The server exposes a simple endpoint allowing operators to flip CDN priority in real time without reloading the player or losing buffered content. The method relies on native support in hls.js version 1.5 and above, with the full implementation requiring roughly 40 lines of server code.