Amazon Advertising (formerly AMS or Amazon Marketing Services) is a service that works in a similar way to pay-per-click ads on Google.
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.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Stripe offers online payment processing for internet businesses as well as fraud prevention, invoicing and subscription management.