There is premium processing for a lot of employment-based visa applications and H-1b is one of them. So basically, you typically pay the USCIS $2,500 and you should get a response, not necessarily a final decision, within 15 business days. A lot of times what happens is that close to the 15th day USCIS will send out what's called a “request for evidence” simply to comply with the time constraint. However, “premium processing” is a great way for typically having a final decision within a month or two after filing.