For those of us who want to start an indie one-person SaaS, this is sobering - because it means that for a while, you’ll be doing all 50 of these jobs. And, paid far less than any of them.
For example, you don't need any of the management jobs until you've hired enough people that you have to manage them. You don't need to do sales and customer management jobs when you have no sales and no customers. Etc.
Of the job titles that remain, these are all specializations. The projection of the work that you'll be doing onto any of the roles will be so small, that there's no point in even identifying it. E.g. you're not really doing "Dev Ops/Infra" if your project is running on a single server in whichever cloud you had the most free credits for.
For a indie one-person SaaS, this list is useful only as an identification of broad areas of concern. I wouldn't even try to read anything from relative number of any type of positions - jobs don't scale at the same rate. E.g. sales workload may grow faster than dev workload in B2C, the opposite in B2B.
Really, you only have about five roles:
- make the service - run the service - market the service - accept money for the service - support the service
and a little later, talk to a pro about taxes.
Next time may just stay a 1-man show, tempeting for sure.
If you want to go indie you can make similar choices to Basecamp (read It Doesn’t Have to Be Crazy at Work) and stay lean and small.