There is a blockchain fintech startup that somehow found my profile and wants to interview me for a senior tech role.

However, I don't understand their business at all, primarily because I don't understand finance and blockchain at all. I have always avoided investing/speculating in bonds, stockmarket, etc. because I'm pretty broke to begin with. I think they would be a huge time sink for no benefit when I don't have leverage. I also have only a very vague idea of blockchain (I have never even read how Ethereum's smart contracts work, for example).

What kinds of questions should I be asking them and myself to consider whether to join that fintech startup or not, assuming I *could* get an offer?