The decision likely got made before performance was a major constraint.
As I understand it, Instagram is a python codebase and (guessing) may be the primary motivator here.
Probably the first, say, 100 person-years of effort poured into the Instagram codebase were done at a time when product development velocity, not performance, was the main priority.
As I understand it, Instagram is a python codebase and (guessing) may be the primary motivator here.
Probably the first, say, 100 person-years of effort poured into the Instagram codebase were done at a time when product development velocity, not performance, was the main priority.