This is all theater in 99.999% of the cases. I mean, the legal requirement is to prove you can't hire anybody with these exact specs in the US. It's usually complete bullshit - of course you could find an SQL programmer or a Javascript developer in the US, those are not extinct yet, and of course, you do not need any special unique knowledge to fill up a junior position, or at least not one any competent developer can't gain in a month. What happens is that you already know that particular person, maybe hired him as a freelancer, maybe did some contract work, maybe did it as a student, or maybe just like that person for that position. Or maybe it's just a bit cheaper.
So what you do is your write a tailored job description, which apparently requires exactly the same skill set the person you want to hire has, up to specific versions of the database system, you "publish" it, go through the motions (without really making an effort to hire anybody - it's usually not very hard for a knowledgeable HR person to do) and in a while you can get your H1B.
Pretty much everybody knows it's a game - the pretense that the only reason foreign people are hired is because there is absolutely not a single matching candidate anywhere in the US is false, but it is impossible to prove. But the game continues because the industry does need the influx of foreign talent, and the only politically viable excuse is the one we have. So we have this game.