I've always been paid, however I now check to see if startups have actually filed the SEC paperwork when they claim to have raised a round, and verify with the investors they claim to have backing from that they've actually invested in the company. One startup I worked for lead the employees to believe we had a solid 18 month runway, when in fact the founders were covering payroll from home equity lines of credit. They didn't actually close the round until a year after most of the initial employees left as payroll became erratic.
Another startup I worked for on the basis of a handshake...never do that. After a year of developing the company's MVP the founder formalized the structure and equity of the company, cutting the four early employees out as co–founders and reducing our equity from 2% to 0.5%. As were were all working on handshakes, none of us had legally committed to working for him, so we all walked away. He lost the MVP since I had the only copy.
The last startup I worked for (and will ever work for), I was recruited by the CEO to come in and build a mixed-discipline technical team in a supporting role. Within a month it became fairly clear that I'd been hired over the objections of pretty much the entire management team, which had I known I wouldn't have taken the role. I was clearly pegged as "a bad hire" which would not have happened had anyone I'd interviewed with spoke up.
Throwaway account…