Immersion is the right path. But wouldn't be better to spend each of the next 12 years in a different country (feasible if you're a top programmer) rather than swapping every month?
Again, if you're a prodigy it can work.
Or is this all a parallel to learning technical languages?
It would be better, if my goal was to know these languages. But, as I've said, I don't much care about that. Learning languages is an intellectually stimulating, past-time activity. If I learn something, great. If I don't, also great.
Also, I don't like planning too far ahead. Usually, I draw the limit at about 1 month, so 12 years is a very very long period of time.
Again, if you're a prodigy it can work.
Or is this all a parallel to learning technical languages?