“ But by that logic, if the language they had been most familiar with was Fortran, should they have used Fortran for Facebook” Absolutely. Otherwise they would

“ But by that logic, if the language they had been most familiar with was Fortran, should they have used Fortran for Facebook” Absolutely. Otherwise they wouldn’t have been able to release the actual product and keep adding features to it the way they did with Facebook. They’d spend half the time learning the “right” language & environment. That would have slowed them down to the point they wouldn’t have been able to work on the actual product as much as they did. And feature-wise, Facebook evolved really quickly.