How a Simple Notification Polling Loop Can Generate Millions of Wasted Requests

A common pattern in SaaS development involves polling a server endpoint every few seconds to check for new notifications, which works fine at small scale. As user numbers grow, however, the request volume multiplies rapidly — 5,000 active users polling every 5 seconds generates 3.6 million requests per hour. Studies of such systems show that up to 95% of those requests return empty responses, meaning infrastructure resources are consumed purely to confirm nothing has changed. Engineers debate replacing polling with alternatives like WebSockets, but the core tradeoff is between low development cost today and higher infrastructure cost as the product scales. The broader lesson is that architectural choices are ultimately business decisions, and polling is neither inherently good nor bad — its value depends on the growth stage and priorities of the product.