Yeah if you're okay playing game of thrones and don't particularly care that the company you work at might not be serving a viable market, headcount is a good metric to go by.
Thanks for taking the time to check out this list and for commenting about it :).
Revenue growth and profit growth would be awesome metrics to have but those aren't publicly available for most of the companies on the list.
I think employee growth is the best objective metric because it captures fundraising and/or profit growth in one combined metric (because companies that are hiring either raised money, are making money, or perhaps aren't good at running their business).
This is really just a starter metric to compare thousands of companies to each other but obviously if you were going to join one of these companies you would want to do much deeper due diligence.
Perhaps revenue-growth and headcount-growth are proxies for different aspects of the company?
For example, revenue-growth might signal how long the positions are likely to last, and maybe something about chances of the company being acquired.
Whereas headcount-growth may be a better signal regarding how much the organizational / management structures will need to change, and what the odds are for carving out your own role amidst the chaos.