Can we get real-time notifications without using WebSockets? Is that even possible?

Hey everyone, I'm working on a project that needs real-time notifications, but I'm trying to avoid adding WebSockets if possible because they seem kind of complicated. We're already using Redis for caching, though. Has anyone here managed to get near real-time updates working without WebSockets? I'm thinking about things like polling really often, Server-Sent Events, or maybe even a clever use of Redis Pub/Sub. I'm really curious about what trade-offs you ran into, especially when it came to scaling things up and how much system resources it took.