How do you build an active and engaged developer community? What is your take on Developer Evangelists?

My take on this is assess what's already out there before building something new. Your team could benefit from becoming active in preexisting communities, building content for them, or sponsoring workshops instead of building something from the ground up. My example for this is when I was first launching Crossbeam's Slack App to the market and we wanted to educated the app developers about the product. We partnered with Slack and our engineering team to author a series of blogs targeted for the Slack App community. This resulted in a surround effect where we were able to impact the dev community who in turn go their teams excited about the App and increased utilization.