If an app says that Instagram was actually written in Python (Django), why do people now say that you have to learn Java?

It is definitely true that the initial version of the Instagram App was developed in Django but the latest development technology such as Java has become popular over time. So the main reason people insist on learning Java for Instagram like mobile app development is that Java offers optimum performance benefits in comparison to Django.

Python has its own benefits for mobile app development such as simplicity, ease of use, and accessibility. As per latest trends, most of the android mobile app is developed in Java or Kotlin and the iOS app is developed in Swift.

So feel free to learn python because there are some requirements for which python would be a better choice for development than Java. So it all depends on your interest and the customer’s requirement for deciding between Java or Python for Instagram like App Development.