What’s the biggest red flag when analyzing a stock?

I particularly look for a combination of two things: Low revenue growth rate AND low/negative cash flow or profit. Although this analysis is a bit simplistic it shows me that the company is not able to utilize it's cash and resources effectively to grow the business.

If the company has high debt/costs BUT is expanding rapidly, future outlook is way different as perceived by the market. If the revenue growth rate is low BUT the company is massively profitable, it signals a mature, stable business that could be worth investing in.

What indicators are you looking for when analyzing stocks? I want to make my process a bit more comprehensive than low revenue growth bad lol.