Some of the most obvious signs that a company culture is toxic are high turnover, micromanagement, and general team misery. Some managers and founders put on a smiley facade and bandaids where ever they can to get you onboard, but it is not long before you start to smell the stench of culture rot.
Building a business culture is hard. There are so many factors to consider when creating shared values and goals across your organization. Defining those goals is easy, implementing the process required to build and evaluate those goals is the hard part.