Declaring a class with a single static method is most definitely not best practices.

Interesting solution
However, I'm not sure if it's quite optimised as it requires recreating string until it has matches
Could've been done via one iteration over the string

Probably worth mentioning if the shifts can be in the past or only in progress/future.
Nice Kata!

Ahah thanks! But what I meant is I actually used the exact same solution from the easy one, but yea maybe I just did it right from the first try :o

That's because you are more clever than I am :-)

Good Kata, but doesn't feel especially harder than the "easy" one :)

I agree. It is not clear if all the dead ants' bits will still remain (i.e. will have moved in the string) or if some of them could be incomplete.

I agree. It is not clear exactly what the output should look like until you see the tests failing.