How do browser games manage API calls on restricted school networks?

Hey everyone,

I've been experimenting with how high-traffic
platforms handle concurrent users on slow or
restricted networks.

I noticed that some browser-based gaming platforms
manage thousands of simultaneous users without much
lag even on school WiFi. I'm trying to understand
the architecture behind this.

Would a FishBase API-style structure work well for
building something like this? Specifically curious
about rate limiting, caching, and how to handle
sudden spikes in traffic.

Any insights would be really helpful. Thanks!