I worked at HBO Max when it launched. Less than 300 engineers, backend services written in either Node or Go. Mostly plain REST calls between services, fancier

I worked at HBO Max when it launched. Less than 300 engineers, backend services written in either Node or Go. Mostly plain REST calls between services, fancier stuff was only used when there was a performance bottleneck. The engineering was very thoughtful and the internal tooling was really good. One underappreciated aspect of simply engineered systems is that they are simple to think about, simple to scale up, and simple to debug when something goes wrong.