While you are in your junior year, work hard to get those top grades. Join engineering groups. Attend events of all kinds. Don't let one or two nay-sayers get you down. Start putting yourself in situations that you've avoided based on fear of the stutter. Note that a stutter moment do not haunt you unless, you think about it over and over. Do networking, be genuine with all: many are watching. It's not too late to get into new events, build comfort, etc. Do job applications now, letting them know you are in your junior year. If someone tells you that it's too early (it's not), ask them for suggestions or tips (there could be something that each company is looking for.. latest software or some other thing). Maybe you'll get invited out for in person interviews. IDK, but it won't ruin anything to start early.