Static site is not the problem. We all know that. It is the infrastructure that you have to setup. The moment you use a DNS server, a web server, CDN etc, you a

Static site is not the problem. We all know that. It is the infrastructure that you have to setup. The moment you use a DNS server, a web server, CDN etc, you are now dependent on their SLAs. So I don't know if you really want to build your own DNS server etc. I would just get may be 3 nice dedicated servers from a provider I trust (either colocate or lease) and then slap nginx in front with may be nginx as a load balancer as well spread across the 3 servers. I can also add something like varnish cache. That way, you are reducing 3rd party dependencies and reducing the added risk (as opposed to using things like other DNS servers, cloudflare, CDN etc). For 3000 concurrent users on a static HTMl site, it should be a breeze. But you are still still dependent on the domain registrar's nameservers and possibly your own DNS server if you setup one.