My answer : -
Minimum logic building is required for interview cracking of companies .
so minimum brain effort is needed as well.
So , all you have to do is complete
all topics popular problems either from love babbar list with help of youtube videos or striver sde sheet .
in 90% cases, same question will come in the interview .
So that should be very easy for you .
After you solve
all popular interview questions like 400-500 ,
then solving slight variations of them will be very easy for you
as you already have the knowledge and tricks in your toolbox.
Its just like 10th board prep ,
even easier than that . if you see it the right way.