their web servers use nginx as their reverse proxy and load balancer. nginx is a high-performance and highly available web server software that can handle a large number of requests and connections from multiple clients. they are also known for their security features such as ssl certificates, http compression, and file caching. nginx has a simple and lightweight design that makes it easy to integrate into existing infrastructure. with a strong focus on performance and security, nginx is often used by companies in the finance and e-commerce sectors.