Each developer relations program has a different opinion on what should be north star metrics to measure the success of their platform. Some metrics are valid while others can be what are called vanity metrics. This post discusses which metrics you should or should not be tracking.
What to Measure
The goal of developer relations is to ensure third-party developers are able to leverage your platform to create something of value. Value can be subjective but some examples include shipping a new integration or plugin that increases the usability of your products or integrating your APIs and SDKs into their web or mobile apps to deliver a better experience for their customers.