Harvard Business Review has some of the best in-depth reviews of individual companies and may offer you some of the information that you seek about an individual Fortune 500 company’s culture. You could start by looking at individual aspects of what is considered part of successful corporate culture and then look for articles or essays about those different facets of corporate culture, which could be a spring-board for an in-depth analysis.
If we were looking at a Fortune 500 company and wanted to find a source of an in-depth look at its corporate culture, we would search for terms like expose, sexism, vacation time, benefits, etc. Finding out specific information about the company provides more insight into corporate culture than reading their HR page’s information about culture. Some companies, such as Apple and Facebook, are known for their unique approaches to employee culture, while others are renowned for their treatment of their employees, including Starbucks and Costco. Choosing one of these companies will yield you more results.
If we were going to write an article that could provide an in-depth look at corporate culture, we would probably focus on Tesla. The magazine Wired did an expose on the corporate culture at Tesla in 2018. It caused a tremendous splash in the tech world, with Elon Musk firing back at Wired for what he perceived were inaccuracies in the article. This type of expose article does a better job of providing actual examples of a company’s corporate culture than an aggregate review, though you might want to use those review sites to determine if the aggregate reviews backup the type of information that you find in an expose article.