Out of my own curiosity, where would I seek a 75-90k salary where the cost of living doesn't negate the increase?
I would say you don't even have to move (although Seattle might be a good choice), but you'd have to find remote work.
Do you have a Github and LinkedIn profile? Put Go, Node and front-end expertise on there but don't say you're looking for a new position. When the recruiters start contacting you, let them know you're open to remote work ONLY if they can get you 90k+. They can get you this. State that it HAS to be remote in your initial contact and don't waiver.
Alternatively you could spend a couple years in the Bay Area or NY and build up a great network then move back as a consultant or remote employee.
Another negotiation tip: The recruiters will ask you how much you're currently making. DON'T tell them (you can after you get 100k+ :). Tell them "I'm not currently looking for work, but if you can find me something 90k+ I would be willing to take a look". Be nice but be firm.
http://www.amazon.jobs/results?str=machine%20learning
Goodluck! Also, feel free to PM if you have any questions.
You should demand more, our field pays more. Don't let your location hold you back. Move if you have to, but possibly switch to a different stack.
Junior devs should be making no less than 75k regardless of location and really, if you're good, 90+.