[anovikov]

It's very different, varies country by country. In UK everything is concentrated in London, in France most is concentrated in Paris but to a lower degree, there is no pronounced hyper-center of everything in Spain - Madrid is top #1 but Barcelona is close 2nd and there is a lot of business and a lot of stuff going on in Santander, Valencia, Alicante, and so on. In Italy Rome and Milan are about equal. In Germany there is totally nothing resembling a dominating city at all. In US it's mostly coasts vs flyover states, hyper-centers do exist by they specialise by industry - everything about tech is in the Valley, everything about pharma is in Philadelphia, and so on - but in Russia, Moscow is a hyper-center of everything, of every industry.

If you are in software startup field and not in the Valley you don't know what you are doing.

If you are in Russia and not in Moscow, you don't know what you are doing - regardless of what exactly are you trying to do.