Ask HN: How to estimate financial health of new company before joining?

My first job was at a startup 15 years ago (<30 people). I was employee number #1 and knew the co-founders pretty well. Because of that, I either had access to financial information other employees didn't have or I could tell if something was going wrong.

Since then I have been working for larger companies and never had to worry if they were going bankrupt. I survived layoffs and other cost cutting measures without much stress.

Fast forward to today, I'm thinking about getting a job at a startup again. It seems "startups" now can have 200-300 employees and be only 1-2 years old. I get a bit scared because they could be burning money fast and I'd be out of a job.

What signs would you look for to determine the startup you're considering joining isn't in financial trouble?