It could definitely be possible with some kind of niche technology consulting company. I'm limiting it to niche technologies because, like others have mentione

It could definitely be possible with some kind of niche technology consulting company. I'm limiting it to niche technologies because, like others have mentioned, operating at any significant scale will eventually necessitate specialization, even for a consulting company (marketing to acquire customers, designers to build good looking software, managers to shield developers from abrasive clients, etc).