[sherm8n]

You're not underpaid, but you could be making A LOT more money. A lot of the suggestions seem to be learning how to do backend development or other skills. You could become a badass full stack developer, hone your skills and then apply for other positions. But why wait?

Talented developers are known for being able to pick up any skill they can on the fly. So you're not really at an advantage spending months or years becoming really good.

The problem is many developers aren't good at marketing themselves. You don't really need to be an expert at something like MongoDB, Backbone or any other technology to get paid more. You just need to clearly explain that it will be no problem picking them up because you've worked with dozens of other no-sql data stores or javascript frameworks.

You want to demonstrate the business value that you can provide to them -- like hiring you will finally allow them to work on that feature that will increase sales by 20%. If you can convince an employer of that, they'll pay you lots of money. An extra 15-30K salary is nothing for companies at that stage.