ATV Posted, this includes Flight Model Interview (the ones that will come on 2.0): https://www.youtube.com/watch?v=p-mifFQpeiw
I think it's the min 12:46
They had reached 100 Employees around March/April last year, 200 on February this year. So it hasn't been for years if you call it hundreds, it will be 2 years of +100 employees on around 6 Months.
In September of 2013 CIG had 80 in house employees, and more contractors.
https://forums.robertsspaceindustries.com/discussion/59057/how-many-people-work-for-cloud-imperium-games
By September of 2014 they had 270-300 in house, with even more contractors.
So yes years.