Your app worked fine when it was just you clicking around. Then real people showed up, and now pages hang on a spinner, images pop in one by one, and someone tells you "it feels slow on my phone."

This is one of the most common problems with apps built in Lovable, Bolt, Replit, v0, Cursor or Claude Code. AI builders are great at "make it work," but they don't think about how much data, how many images and how much code your app sends to a stranger on a phone. In a January 2026 r/lovable thread, a developer described a client app that slowed to 30+ second page loads at around 1,000 users. The causes were boring: one endpoint returning every record, a database call per row, and no pagination.

The good news: boring problems have boring fixes. This guide walks you through 7 steps, in the order I'd do them, with copy-paste prompts and short code.…