Slydeways has many builtin features that make it one of the fastest themes on the market.
There is a section in the customizer named: Speed Optimization
It has three different settings for speeding up your website.
Use Font Awesome CDN (recommended)
This theme ships with all the fonts and assets needed without the need for CDN’s, However you can use CDN’s (Content Delivery Networks) to speed up downloading times for users. This change affects the the Font Awesome Icons.
The Font Awesome fonts can be downloaded from the CDN by just gong Customize > Font Styles > Use Font Awesome CDN.
Load jQuery in Footer (recommended)
WordPress comes with jQuery and it is usually loaded in the document head. Loading jQuery in the footer increases site speed but could be incompatible with one of your plugins. Please test and if your getting a jquery error or if your plugin requires jQuery loaded in the document head uncheck this box or find a better plugin. Read about render-blocking JavaScript and CSS in above-the-fold content for more information.