Sometimes you know. You don’t know how you know but you just know.
Recently, I accepted a role. I had my stomach whirling like a police siren but I chose to ignore the signs. To this end, I ended up regretting my decision.
When a company tells you they cannot tell you about their client or their projects due to NDAs, while in all truthfulness sure, they might not be allowed to share, they can still paint some sort of picture for you for what you are doing.
Steer clear and away.
I learned the hard way.