Personal experience.
Our company in Japan decided to make a crypto currency.
We are not a big company, maybe average, and we had no knowledge of the crypto currency.
We began to study crypto-currencies, their capabilities and potential after the official recognition of the government of Japan bitcoin as a method of payment. Starting at May 2017
May 17 - reading
June 17 - even more reading
July 17 - reading and learning the right skills
August 17 - Planning Strategy
September 17 - tests and tests on the local server
October 17 - is a fist good result
... near future ...
November 17 - Testing
December 17 - perhaps the first launch
Total: 8-9 months from the full zero point of C ++ knowledge, before the release of the crypto currency. It's like giving birth to a child.
And yes, besides that, we were still engaged in our main work.