So now you have gone through it all - you will have built a back-office SaaS stack that can take you from idea, through funding, through the first ~50 or so headcount before hopefully you bring on a CFO or epic COO to transition to the tools that will take you from start-up to true scale.
TLDR: Link up with a top notch banking team, incorporate as a Delaware C-Corp with a streamlined online tool, sign up for a credit card, link it to an expense management tool, and that into an accounting software, add the bill pay tool, launch payroll and benefits and tie it up in a bow with a bookkeeper (or do it yourself) and you have conquered the stack.
With all of these subscriptions assuming that you go with a bookkeeper and have 25 employees and regular flow of expenses your cost might look like this:
Quickbooks: ~$70/mo or $840/yr
Bill.com ~$120/mo or $1,440/yr
Gusto: ~$339/mo or $4,068/yr
Expensify: ~$225/mo or $2,700/yr
Carta: ~$230/mo or $2,800/yr
This stack will cost you less than $40k a year. It's an integrated set of tools that work together to flow into a single source of truth, managed by a dedicated bookkeeper who keeps on top of accuracy. Frees you to build your company, solve the problems you set out to solve and focus on the important things.