The biggest structural difference is you have to hire all the VPs by employee 50–100. You won’t be able to scale this far without a full management team — VPs of Sales, Marketing, Product, Engineering, Customer Success at least.
But the toughest personal challenge for many CEOs is letting go. By employee 100, you have to let go of things. You have to let go of being the product manager. You have to let go of what you say being almost divinely correct. You have to let go of the many mistakes which will be made. You have to let go of the fact that some important things will be done “worse” than if you were doing them or managing them yourself.
You have to let go, and learn to backfill the team you build.