A page that feels instant with a few users can become painfully slow when your business grows. The code hasn’t changed. The server hasn’t changed. The database hasn’t suddenly become bad.
The difference is scale.
More users. More records. More requests. More data moving through the same code paths.
Most performance problems don’t appear when you build the feature. They appear months later when real customers start using it with real data. A page that loaded in milliseconds during development can take seconds in production because the application was never tested against realistic conditions.
The problem is usually not the server.
