I have not understood yet the following with regards to H1-B visas.
As far as I understand, you have to be hired by a company in the US before April because in April the lottery for the visas is taking place.
But you can only start your job with your visa in October.
How is it possible that a company will be waiting for you for six months?
Most companies in London want you to start at most in one month after you are hired.