I've been a solo founder for some time. By far the toughest thing for me has been the cognitive load.<p>I don't mean raw time. I generally have enough time to get done what I need to get done. I'm talking about the sheer number of different things I have to think about and pay attention to. It's more about mental clutter and management of it than time management, at least for my own case.<p>Burnout can be an issue too and can come from cognitive load and also not having as many peers to give support and energy. It's easy to get down and lose motivation.<p>Overall I'd say: multiple founders with good chemistry > solo founder > multiple founders with bad chemistry or conflict. I always put being a solo founder on a list of weaknesses, but the thing is that everyone and every team/venture has a list of weaknesses and part of succeeding is recognizing yours and trying to work around them.<p>Strategies I've found include maintaining time/energy boundaries (e.g. not working weekends unless something is on fire), delegating where possible, managing scope creep (I've had problems with this one!), and looking at it as a marathon rather than a sprint and thinking in terms of endurance. Getting exercise, eating healthy, and trying to get enough sleep help too as with anything requiring one to be fit.