What roles can't a startup do without?

What roles can't a startup e.g. small to mid-sized business with online presence, do without? If you're thinking of starting your own company, here are the five people you shouldn't go to work without. And some people they might need.

DevOps

S/he launches the stack and makes sure it takes off every time you log in. Don't even try starting an online presence without her/him. Must form alliances with white-hat hackers. Being one is a plus.

Data Scientist

Vital to the whys and hows of your startup's collection and use of data. Should have an ear for how this stuff can stuff your banks...or make you a target of the law.
Possible teammates: data analyst (who turns ggPlot graphs into dynamic presentations) and quantitative developer, depending on the worth of your data, e.g. passwords and money. So...yeah.

Full Stack Developer

Served sites or apps? How about desktop interfaces? The modern FSD is a savant on everything from scaling to load testing to webAssembly and everything in between. Must be allies and comrades with DevOps and....

Full Stack Designer

Range on the stack is basically above the SQL level. The full stack designer's obsessions are the user experience and how it represents this company. Design knowledge must be vast. Yes, this is basically UI/UX but with the ability to turn this into served, debugged reality.

Growth Engineer

Typically described as a full stack developer with marketing skills. Isn't that a full stack designer? Not exactly.
The "growth hacker", all grown up! The code "ninja" who's actually invested in the company doing well. Which...is how it should be anyway, but OK.