Comment by jrochkind1

I have never worked in any problem space where it _wouldn't_ take a senior developer a year to become fully competent.

Unless by "Senior developer" you mean someone who already has experience in the problem space, of course. If all you do is ecommerce, then, sure, you're already competent at ecommerce (at least hypothetically you could be) because you've already spent more than a year at it.