Everything you describe is fantasy, though. It’s not real. It’s not possible to be real. “Give me a new billing system”?? No way is that going to produce a good result for the company or their clients. But the second that Joe Schmo has to start laying out all the ever-evolving requirements for his custom billing system, he will run back to traditional SaaS providers.
At best, if AI is supergenius enough to just intuit everything Joe needs, then the cost of running the AI to constantly maintain a billing system will far exceed the cost of just paying someone for their existing billing system SaaS.
I think the idea is you'd basically have it take a look at your current system, it would learn what features you're actually using at all, it'd check company emails for past and current pain points or stuff you wish was possible or just simpler, it'd Slack everyone in the company asking what their biggest wish and biggest pet peeves are currently, it'd do a small interview with Joe himself presenting the above to see if it's gotten the right idea, create a very detailed spec and then implement it.
Of course both models and tooling will need to be far more powerful for all this, but it doesn't exactly seem sci-fi to me.
Once system is built it could run detailed analysis on its usage and figure out what parts seem to be confusing or slow for users, and simply refine, deploy, keep analyzing, rinse and repeat.
The biggest upside is probably that workers could also simply request features, have Joe sign off on them (would get messy otherwise) and minutes later they actually roll out.
To me anyways most systems are a PITA because they do so much and your own organization only utilizes a small subset. Good systems actually let you turn off stuff you don't use so that users don't even know it's possible and don't have to drown in menu options, but that's still rare enough. And good luck getting dev focus on your specific requests regarding the parts of the system most important to your specific company, since there are a zillion other things and hundreds or thousands of other customers.
Something literally tailored to what you need will surely be the norm eventually. In five years or whatever I'm sure we'll be plenty on our way towards something like that.
But again just like LLM training in general this all requires having something existing to analyze and work off of. So yeah nobody will be going from paper to custom agent-built system.
Other idea:
Stay with SaaS, real devs, real core product, closed source, but each customer can (if they want and pay up) literally skip multi-tenant and being on the same codebase as everyone else, and get an interface to actually customize their own version to their liking.
Remove unneeded features, change UX, UI, add features. Some dev spends tiny amounts of time ensuring nothing gets too crazy, but apart from that it's basically an autonomous fork of the product, continuously tracking main.
It's science fiction, because when you have this capabilities you don't need any payroll system, you just let the AI do the job Joe was doing.
The system you are describing is far more intelligent than Joe, there's no point to use it to solve a operational problem, just point it to the problem Joe is solving.
Or even better to the problem that create the need for Joe role.
doesn't matter if it's just some agent using the system in the end, you do understand you still need an actual system for consistency etc, right?
Just that instead of cirrent "making something possible" it'll mainly be for restricting what's possible, hence forming a stable format.
That will never ever stop being a thing, even if the inputs and possibly outputs are entirely rock n roll it still requires coercion into something suitable for storage and processing.
At best, if AI is supergenius enough to just intuit everything Joe needs, then the cost of running the AI to constantly maintain a billing system will far exceed the cost of just paying someone for their existing billing system SaaS.