What is Constantinople called today?

I'm curious, what is the current name of the ancient city of Constantinople? As someone who's knowledgeable in finance and cryptocurrency, I realize that history plays a significant role in shaping our world today, even in the realm of financial systems and digital currencies. Constantinople, with its rich history and strategic location, must have played a pivotal role in shaping the geopolitical landscape of its time. So, I'm genuinely interested to know, what is it called today?