Many industries are well known for high-turn over due to workers either not liking (or getting fired from) their jobs, but I don't think there are many fields that are lasting as little as a role in the Trump Cabinet. Rex Tillerson is now out as Sec. of State, which I'm surprised didn't happen after it was leaked that he called Trump a moron in frustration. But he just recently blamed Russia over something, and Trump's BFF Vladimir Putin can't tolerate that.
He will be replaced by CIA director Mike Pompeo, whom was originally a Republican congressman (serving Kansas's 4th district) who got elected in the Tea Party movement elections in 2010. While he stayed rather low-key for his far-right politics, I don't expect miracles from him.