Comment by axismundi

From my experience WebSockets are harder at scale. For load balancing you either need sticky sessions or an L7 proxy that can route consistently, and reconnect storms amplify this. Long-lived upgraded connections mean more complexity with rolling deploys, drains, autoscaling, and regional failover. Many managed LBs/proxies have tighter limits/timeouts for WS, so you must tune idle timeouts and ping/pong.