I can't even access the lemmy.world instance. It just always errors out for me.
But I like the idea of smaller servers that specialize in a specific hobby/interest/topic and then all the /c/ communities can be centred around that topic and moderated appropriately. I think it leads to better discussion between people looking for programming topics.
Personally, I would say if you have experience in the field (sounds like you do), then the best you can do is keep trying and try to fill in the gaps where you know you're lacking (and discovering what you lack though the interview process).
Ultimately, it seems tech is going through a bit of a slowdown in the hiring of new employees right now, so its not as easy right now than it was for the last few years. As such, competition is much higher than it was, and even if you're a strong candidate, you will likely need to apply to a lot of roles to get where you want to go.
Just don't give up. :)