I was learning Python and came across something called Cython helping to gain performance improvements. Later, I found this talk https://www.youtube.com/watch?v=_1MSX7V28Po presented by the developer of Instagram and during his talk he said that Cython is truly helpful in terms of Python optimizations. But briefly mentioned that if you just add Cython is good but if you add types annotations for your python code. You can achieve much better performance. So, the question is Is it true that by just adding cython we can get performance boost BUT if we add TYPE ANNOTATIONS for python code, then performance boost will be much more better?