Disclaimer: I'm making a lot of assumptions and you're seeing a lot of my personality here and naturally you don't have to agree with any of it. That's why I say: I am just one feedback point. What I'm good at is being honest. So here it is.

Also, I have no clue what would be a good job posting.

My thoughts:

Who are you looking for? If you're looking for someone that wants to extend their personal life into their working life that has a particular personality, then this job ad seems quite good for that. I bet you are that way. I suppose you want more people like you, nothing good/bad about that, just my thoughts (it can be good/bad depending on circumstances).

Also, I'm not judging, I don't know enough to make any accurate assessment about whether that's good or bad. I just look at the market dynamics that I can glean from the job market and this job ad.

It also reads very American as work-life balance seems to be a bit more blended and/or bad.

Now let's personalize it to me, since I don't know enough about anything else. I'm not a UI designer but I happen to be interested in it. I'd never apply to your company (unless the salary is twice as much as I make now or if I'd be in a desperate position), here is why:

This job ad also makes me feel that you guys have no clue about the power balance between you and an employee.

Here is how that power balance can look like:

Let me tell you that getting fired sucks (I sort of have experience with it). Why does it suck? In my case, because I didn't don't know if I'd be okay in the future. It took me 18 months to find a job (with a master in CS even) and after 7 months was not extended. I was down on my last dime after searching for 6 months again. What would I need to do? To steal? I don't know. But I'm not going down without a fight. Welfare is a thing in my country but I've seen how it gets distributed and I know how raw things can get based on what I've seen with others. I'm not going to be a passive homeless person (I'd rather not exist). Luckily for me, I got a job again after 6 months so nothing like this came to fruition and I'm currently financially in amazing shape. It'll be hard for me to ever get homeless.

In any case, that was my situation. Whenever I'd read a job ad where I was treated as if we're all equal, well, we're not. Because if you (the boss) say something fucked up, then if you don't believe it is being fucked up and someone calls you out on it that employee is what we call in a perilous job situation and will possibly get fired by continuing that behavior. Yet, you can still be abusive without knowing it. So we're not equal.

Professionalism comes down to keeping things clean. I was working for a CTO once that would play Ramstein in the whole office and we all had to listen to it. I quit that same day after hearing the 5th dick joke. I like Ramstein, but not when I need to concentrate. Their humor was on point and had great technique but also felt very offensive to women. But we're all guys right? Well, yes, but I know many women and I like them. Ah it shouldn't matter. Okay, so what if I joke about a family member of you dying from cancer? Oh that matters? Really? So you can be a psychopath about one thing but not the other? I call that being egocentric. But all of this is solved if you simply say: let's keep the jokes clean and the working environment clean. Professionalism feels very sterile because of it, but it helps for a conductive and collaborative work environment because people don't get emotionally fucked by other people their emotional quirks or abusive tendencies.

And don't get me wrong, you can talk about your personal life, but still keep it clean. My current CTO for example said once during the standup that he had a very shitty weekend (since we always ask "how was your weekend?") but he didn't go into it and I could only imagine. I find that much better than if he'd delve into it during a standup. Yet, another person did mention his climbing trip and went into that.

Those are some of my thoughts. I have more but explaining my assumptions takes a lot of time to write and read.

I hope this helps somehow.

I think it's awesome that you're asking for feedback. Though, it can be a double edged sword. In most cases, the crowd knows better than you, but feedback becomes tricky if you actually know better than the crowd but don't have the confidence to believe that.