I had a similar experience. I was brought on as a junior fresh out of university and quickly made a name for myself in the company, I wasn't the top developer b

I had a similar experience. I was brought on as a junior fresh out of university and quickly made a name for myself in the company, I wasn't the top developer by any means, but after a few years and a couple of pay rises, the £32k/year they were paying me (in central London) was definitely much lower than what I should have been getting. One of my colleagues had the year before, and had recently got funding for his startup. He offered myself and another developer a job, so we went to tell our boss together who obviously wasn't too pleased. He then spoke to us separately about negotiations, and he offered me £55k/year. The look on his face when I said "Sorry, but they are offering me much more than that" was priceless. A few years later (after all the team I'd worked with had left) I went back to what was left of the company as a contractor for a few months. I was earning more per week, than I was per month, when I first started.