Got it, thank you for the feedback :)

I will unpublish the kata to save it from collecting even more negative feedback, and I will try to explain you why idea behind the kata might be not that good:

First of all, it will be very difficult to enforce a specific implementation. How are you going to test whether a user implemented karatsuba algorithm? It's not enough just to ask politely, your tests have to actually verify it.

Python, and many other languages, have big integer operations built in. How are you going to verify that solution does not use native or library big integer?

Additionally, big integer multiplication kata already exist. You need to be careful to not make your kata a duplicate.

This is just a copy of the "Multiply" kata.