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

Fly is a platform for running full stack apps and databases.

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.

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.

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

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.

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