A hard change is the required skills mix.

Early stage you want the generalists who can do everything, move fast and probably break things.

There's an inflection point where you want to stop breaking things and for that you need specialists. Experts in scaling, security, optimisation and code purists.

Finding new roles for your generalists at this point could be hard, even harder will be having to let them go. It's possibly something you should consider at the start and give them the ability to vest and leave for a new greenfield. Alternatively find them a role as an architect/lead where it's their responsibility to be across everything and able to bridge between teams because they have your domain and institutional knowledge.