I don't think there is a good answer to this, unfortunately. I can't speak as a "solopreneur" because I'm not that, but I'm a consulting engineer doing platform and infra-layer work for small businesses that don't have the resources to do it themselves, and I can at least say where and why I see them fail.
Largely, they have the problem you have. They don't know how to hire. We get some initial POC/MVP services up and running, but then it comes time to monitor, secure, upgrade, actually run the software for the long term, and they try to bring in people who can do that, but don't even know what to ask in an interview because they have no knowledge of these fields of practice themselves. The main company I'm working with right now has hired three guys to try and do all of the basic maintenance and daily operational work and they've so far fired all three. They either messed up badly from not knowing what they were doing, or at least realized they didn't know what they were doing, but also couldn't learn, and this company doesn't want to be wasting the money they're spending paying me to be a teacher, and I don't want to be a teacher.
I think my advice would be advice a lot of solos don't want to hear. Unless you're a genius polymath with at least inch-deep knowledge of virtually everything related to computing, which gets harder and harder as time passes and there is more to know, don't try to do it alone. Have co-founders that augment your gaps. Technically competent investors with expertise in how to staff at the executive level so you'll have others with you who at least know what to look in staff and how to hire, or can help you separate wheat from chaff if you're trying to use headhunters.
Also, don't be in such a hurry. Whether it's get more runway, cut costs elsewhere, I don't know, but take your time and do it right. Going through cycles of hiring the wrong person, having to fire them, and then doing it all over again, is disruptive, destructive, and will get you a bad reputation to the point no one reputable will even want to work for you.
Otherwise, your best shot is to get lucky. That happens enough at scale that the market is full of people who got lucky, but it doesn't mean the probability of success is high when explicitly using "get lucky" as a strategy. You can't just look at what the top people did and copy them any more than you can watch Usain Bolt's training videos and hope to become a great sprinter by doing whatever he does.