FAST IS A DESIGN DECISION

Summary from the TLDR Design newsletter

AI has made websites dramatically easier to build, but generated experiences can still impose substantial costs on users through slow servers, excessive JavaScript, poorly prioritized media, ineffective caching, and other performance problems. Many of those costs originate in design decisions such as autoplaying video, multiple font weights, media-heavy carousels, and animations, making performance something designers should actively budget rather than leave entirely to engineers. Understanding a few fundamentals around rendering, CDNs, caching, loading priority, JavaScript, and real-world device performance lets designers and AI agents make deliberate tradeoffs between visual ambition and speed.