Ask HN: Which skills are essential for a developer to join a blockchain startup?

I don't know if there is any future for blockchain or not, but there might be and I am currently a bit bored of what I've been working with so far, so I thought it might be interesting to work with something as new and undeveloped as blockchain just to get that "hacker" feeling back, which I had when I started with web programming back then.

UPD: could you keep your sarcasm to yourself, please? It's not a place to discuss how much of a bubble everything blockchain-related is.