Extraordinary! Congratulations. I’ve always been fascinated by the world of telephony. How did you manage to get numbers for every country? Do you have direct access to SS7, are you a virtual operator, or do you use third-party services for each country?

Usually, you need a presence in each country, like an official entity. It's easy for a myriad of countries to do that for a fee; even in Dubai, you can form a company. Then you can acquire numbers easily in these countries. I am now supporting the UK (easy to get)/US/CA, and will soon support some European countries as well. What's hard are the countries that require authority talks like Egypt :D

I am Egyptian living in Europe, so I want to support it, but I left it for a bit.

There are a lot of telephony providers out there (Twilio, Bandwidth, etc.) So it's easy to start building.

He just uses Twilio, they handle everything, he just calls some APIs and takes a 257% markup for phone calls. Anyone can sign up, usually at most you'll need a local address.