TDS. What is needed for fault tolerance?

Question

Programming

Hello!
There was a need to write my own TDS (traffic distribution depending on geo, devices, browsers, etc.) Before looking for a developer, I would like to know about a bunch of technologies that are most suitable for this task.
Of the main requirements - fault tolerance and scalability. At the moment, there are about 5 million visitors a day on the grid of sites. What is the best webserver to use? What is the best way to write it and what is better to use for caching? What about the base and its optimization? Should You Use Frameworks? Where is the best place to find an artist?
There are no problems with iron, it will be very good if you can orient the server config for this task.
Thank you.

Answer 1

Of the main requirements - fault tolerance and scalability.

Cloudflare is a recipe for 99% of cases.
And when you outgrow it and you no longer have enough of it (I bet that this will not happen very soon), then ask questions about specific problems with it and about what you lack in it.

Answer 2

For starters: bgp, anycast, nginx