Fastly largely runs on Varnish, it seems: https://www.fastly.com/blog/benefits-using-varnish https://www.fastly.com/blog/benefits-using-varnish >At the core of

Fastly largely runs on Varnish, it seems: https://www.fastly.com/blog/benefits-using-varnish https://www.fastly.com/blog/benefits-using-varnish >At the core of Fastly is Varnish, an open source web accelerator that’s designed for high-performance content delivery. Varnish is the key to being able to accelerate dynamic content, APIs, and logic at the edge.