PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.

Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.

Amazon Web Services (AWS) is a comprehensive cloud services platform offering compute power, database storage, content delivery and other functionality.

Amazon CloudFront is a fast content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to customers globally with low latency, high transfer speeds.

WebSocket is a communication protocol that provides full-duplex communication channels over a single, long-lived connection, enabling interactive communication between web browsers and servers.

LiteSpeed is a high-scalability web server.

Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.