Can you explain Developer Marketing to someone who is hearing the term for the first time?

How I described developer marketing in new hire onboarding at a previous company is that a developer platform gives someone the ability to customize their needs in a particular software product. And there’s both a business and consumer opportunity to this.

For example, at a previous company we were buying email delivery software and I met with two market leaders. Both did about 80% of what I wanted, because they were built for common use cases, but my organization had our own way of doing things. So neither product completely solved our needs. A developer platform on top of either would have given my company the ability to make some customizations to solve 100% of our needs. 

Another example is when you as a consumer use Facebook to log in to a website. With this functionality, the website owner doesn't need to create a login experience and also doesn't have to tap into the entirety of Facebook. 

The Developer is the person that writes this code for a software product. Developer Marketing is how we as marketing professionals excite developers to try new functionality as well as evangelize the work that developers have done to excite customers to try these new user experiences. 

Developer marketing is marketing towards the developer persona. Developers typically hate marketing and will not respond to things like ads, "ship software faster" messaging, and traditional consumer marketing tactics. To be good at developer marketing, you have to speak their language, think about their problems, and put it in the channels they hang out in. Do not copy paste the same marketing plan that you would for an enterprise audience, or a consumr product.