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.
Klaviyo is an email marketing platform for online businesses.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
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.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.