I haven't had a distinguished career in tech, actually I've never even had a job (I build and ship software as an entrepreneur). I think your perspective of ne

I haven't had a distinguished career in tech, actually I've never even had a job (I build and ship software as an entrepreneur). I think your perspective of needing to have a "specialization" is a bit overweighted. First, how did you become a "specialist" in the first place? Go back to the beginning of the path. You probably toyed around with some technology, enjoyed it, and kept doing it. You ended up building a relative knowledge advantage over your peers and fulfilled roles accordingly. However, if you were sufficiently educated, you know that the fundamentals of CS/technology always stay the same. That means even if you specialize, you should be able to catch up to anything else without issue. So rather than looking externally for signals about whether something is becoming dated, it might be easiest to just have a breadth of toys and side projects. You will see things you like, and they will pull more of your time and attention. If those technologies compete directly with your legacy frameworks, you'll know why X is better because you've used both. Being flexible and broad like this allows you to change direction quickly, at the expense of being a single-minded, deep specialist.