When Whatsapp was acquired for 20 billion and was already one of the largest messaging services on the planet it had 50 employees total, 30 of them engineers.
Now granted that's more than five people, but that was a planet sized service. Say you're a company that's worth 10 million or 50 million with a proportionate amount of complexity, you ought to be able to built that with a team of 10 people if you chose your software stack wisely.
Paul Graham has an older piece about Lisp and beating large companies by having a technological edge. Picking your software and understanding architecture can be very important. I have seen Clojure teams of smart engineers in particular in distributed / concurrent systems (the sort of thing that can produce a lot of value) who do as much work in a team of 5 as a big corporate Java behemoth does with a 100 people.
Now granted that's more than five people, but that was a planet sized service. Say you're a company that's worth 10 million or 50 million with a proportionate amount of complexity, you ought to be able to built that with a team of 10 people if you chose your software stack wisely.
Paul Graham has an older piece about Lisp and beating large companies by having a technological edge. Picking your software and understanding architecture can be very important. I have seen Clojure teams of smart engineers in particular in distributed / concurrent systems (the sort of thing that can produce a lot of value) who do as much work in a team of 5 as a big corporate Java behemoth does with a 100 people.