A/B Testing JSONP and the Preloader with RUM
SpeedCurve is a SPA (Single Page App) so we construct the charts dynamically using JSONP. It works great, but we're always looking for ways to make the dashboards faster. One downside to making requests dynamically is that the browser preloader isn't used. This isn't a factor for later SPA requests, but on the first page view the preloader might still bring some benefits. Or maybe not. We weren't sure, so we ran an A/B test. Long story short, doing the first JSONP request via markup caused charts to render 300 milliseconds faster.
