Does Sumo slow down my site? What is async loading?
Sumo Load Times, Asset Volume & Connections
Sumo may appear to add time to your page load but whats happening is called asynchronous loading, meaning Sumo yields to your site, loading as passively as possible, always giving precedence to your site. We do not block any content or scripts on your page from loading. Our back-end is powered by a world-class cluster of web servers with an average response time of 8 milliseconds.
We're always working on optimizing load times and file sizes. To optimize download speeds we use a global CDN (Content Delivery Network) to deliver all of our assets, and utilize keep-alive requests. While there are "multiple requests" being made, they're using the /same/ connection without disconnecting, which has the same net effect as a single connection.
We do not leverage caching for sumome.com/api/load because it is a dynamic response relative to the current logged in user/session/page/etc. it controls the behavior for the current page load, the actual code load.sumome.com/ is cached
We do utilize caching and build our CSS on a per-app basis instead of a singular CSS file for all apps because having you load only what you use is more efficient and optimal. Our CSS is combined per app (for the app and user-facing) because we never want to have your visitors loading the admin CSS. For admin's in particular, there are a lot more assets that load compared to a normal visitor, because of all the additional Tools and UI for using Sumo.
So with everything loading behind a CDN and with our use of caching, the majority of all your visitors will only load our files once. Rest assured, we're fully aware and make conscious choices to deliver Sumo asset's in the most optimal way.
For more information, check out the Google PageSpeed Insight's articles about asynchronous loading: