Where do you advertise your content?

Hello fellow Indie Hackers 👋

Help me build a mega list of resources where we can advertise/link our newest content? I'll start with a few of mine and I'll update the list as comments arrive:

Technical

• https://news.ycombinator.com/submit

Ruby / Ruby on Rails

• http://www.rubyflow.com/#submitform
• https://www.reddit.com/r/rubyonrails/
• https://www.facebook.com/groups/rubyonrailsframework

Python

• https://pycoders.com/submissions
• https://www.reddit.com/r/Python

SEO

• https://www.facebook.com/groups/digitalmarketingg
• https://www.reddit.com/r/digital_marketing/