[kristjan]

Complexity theory had been explored, if not deeply, somewhat before what we'd consider "typical days of programming": https://en.wikipedia.org/wiki/Computational_complexity_theor...

[j2kun]

I suggest you read that more closely. There was no theory laid out until the late 60's, and "complexity theory" was not a field until the 70's. On the other hand, there is a long list of programming languages invented in the 50's.