Almost any implementation feels smooth when the JSON is small. The real challenge starts with large data: a real API response may contain deeply nested objects, long arrays, and many repeated structures. At that point, simply panning the canvas, editing one field, or switching between two documents can freeze the page. While building Treease to work with 50 MB documents, I made a series of optimizations. This article collects the lessons behind them. It focuses on what to compute, read, an...