Amazon Pay is an online payments processing service that is owned by Amazon. It lets you use the payment methods associated with your Amazon account to make payments for goods and services.
Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PHP is a general-purpose scripting language used for web development.
Shopware is an enterprise-level ecommerce platform.
A modest JavaScript framework for the HTML you already have.