How to Scale Sales?

When I got one sales guy, we had one engineer and run a marketer on board. So he used to join all the meetings, but I used to lead those meetings. And then I was shadowing him so that I can help him out wherever there were some questions which he could not address. Once he got three to four deals closed, I thought maybe this is the time, maybe I can add one or two more sales guys. That's how we got to that 50, 60 customers, with 140 and $50,000 ARR.