I have gone from a junior developer to senior to lead and managing a team of developers. Don’t worry about the interviews. Everyone is nervous and struggles. When I am being interviewed I advertise going in that I have a stutter and as I settle in to a position it eases somewhat. When I interview people I am looking for technical ability, social fit and ability to communicate. With the latter it isn’t all verbal, you can lean on a white board or chat to help express yourself. If you are worried about your stutter apply to bigger companies. They have processes in place to avoid discrimination and the budget to support you effectively. Personally I always go into an interview thinking it doesn’t matter, there will be a better offer for me next week and they need me more than I need them. It’s true and helps take the pressure off.