It isn't difficult to meet people who have authority to hire people. Go to meetups/tech events/conferences in your area. Demonstrate value; ask people if they/their firms are hiring or if they know anyone who is. Some people who go to meetups/etc do not have hiring authority, but they often know who in their organization does -- ask them for a warm introduction.
There exists a series of tubes between every engineering candidate and every firm which hires engineers. It isn't like there is a Super Secret Hacker News For People Who Actually Hire People. Same HN. Same Twitter. Same email (probably your best bet for a cold contact). Same phone system. Same Github.
(Passively adding stuff to your Github is a low ROI way to get offers. Find a project managed by your target company, fix a bug or send them a pull request, then try to escalate to a discussion with a decisionmaker in engineering -- coffee or a Skype chat or whatever.)