Such a startup must have a senior developer to start with. Without one, it will fail. Finding the first one is hard if you have no experience and no way to judge the skill of a programmer. But a startup without a first senior is doomed to fail. I do not think it can even start. That first person will impact all that will follow. His thinking and feedback will be used in hiring the next members of the team.
If there is no such person in the company, one should be hired as soon as possible, but the task to find one should be outsourced. Use a company that can evaluate the skill of that first person you get. Once you have a pool of candidates, talk to them and see if you can find someone you can resonate with at human level. Technical skills are important, but soft skills matter just as much. If you are good with people, by talking with the candidates, you can evaluate their level of enthusiasm, reasons for doing a job, life goals, personal intelligence, emotional intelligence. All those things are important. A great programmer that can't communicate, has a hard time in social circumstances, will be of no use as a first dev you hire. Such hackers are great for some projects, but if you want to build a team, you need something else. Something that is more like a CTO, but is still a programmer. Or maybe you just need a CTO in the first place...
Another thing is that in my opinion human qualities are a lot more important than skills, because anyone motivated, will learn a skill it needs. Think hard about what kind of team you want to have and go from there.
But saying that, don't hire nice people that are incompetents. Use external help to filter the candidates BEFORE you try to filter inside based on your company values. Because there are great people out there that are also very good at what they do. Just do not be the one to judge their competency if you have no idea about that field. It will backfire.