Alternative advertisement channels to reach developers. The million dollar question.

Hi there! I have a feature flag and config management service and I believe that my target audience is developers and architects who work for small from large companies.

I'm wondering what what are the best ways to reach them other than putting on paid ads.

i have read online marketing books but they seem like 5 years behind or stating the obvious. :/ meh

Probably this is the million dollar question and I feel like I will have to figure this out on my own.

I'd love a group therapy on this. :D