Fastly is a cloud computing services provider. Fastly's cloud platform provides a content delivery network, Internet security services, load balancing, and video & streaming services.
GitHub Pages is a static site hosting service.
Umami is a self-hosted web analytics solution. It's goal is to provide a friendlier, privacy-focused alternative to Google Analytics and a free, open-sourced alternative to paid solutions.
Varnish is a reverse caching proxy.