How fetch(keepalive) Broke in High-Latency Regions

This is a practical post that actually walks through a real failure mode: fetch with keepalive can silently drop events in high-latency scenarios, while navigator.sendBeacon is far more reliable but breaks promise-based queueing. The author shows concrete evidence (activity logs and a session map) and explains the subtle trade-off between delivery guarantees and ordering — exactly the kind of thing you'd want to read before rolling your own analytics SDK.