Since this is an audience of passionate technologists, here's the top piece of advice I have: Do not be seduced by the technology! I killed one of my startups this way. I've seen many many die this way. It can hurt your pride as a passionate technologist to choose non-cool but mature and easy-to-hire-for tools. But it's those tools that are the most economical. Remember, your customers care 0% about the backend techn…
The downside is it could backfire on who you're able to hire. It could just lure people who will either want to migrate to the next new-and-shiny or just leave quickly.