There are three standard ways to manage API authentication these days: API keys, OAuth tokens and JSON Web tokens (JWT). Adam Duvander over at the Zapier engineering blog explains how and when to use them. The humble API key is the common and earliest form of API authentication.
Question: How did a company that is essentially an API raise $8.2 million? Answer: by smartly targeting a fat market (identity access management in the cloud) that has great need, according to the press release,