As someone who does hiring, I have a different interpretation. Let's say I'm a rails shop and I'm looking for mid to sr. level candidates and someone has 10 years of experience working on Java 1.4 spring based application. I think to myself "this is great, they are willing to do some grunt work but I need to know they haven't stagnated".

It's the stagnation that leads to lower job offers. You need to convince me that you were a dedicated employee for 10 years (which you are), but you also need to show that you're willing to learn something completely different. This can be a side project (doesn't have to be crazy, but slightly more then just going through the tutorial), certification of some sort, or _something_ that tells me you're not just going to write java-esque rails.

I would even go so far as I prefer people with diverse backgrounds, who are really willing to learn, so that we benefit from mistakes they made at previous employers.

> You need to convince me that you were a dedicated employee for 10 years (which you are), but you also need to show that you're willing to learn something completely different.

Have you actually had examples where this wasn't the case? This seems like a common sentiment that I myself have thought, but I honestly can't think of a single instance where a candidate with good experience or knowledge wouldn't actually be willing to learn something new, or wouldn't model code they write along existing idioms.

I can't comment on every sector but it absolutely exists in the financial technology realm. Plenty of people working in tech don't view it as an evolving set of skills and it's common to have candidates come with 1 - 2 decades of experience despite ending their search for knowledge around java 3.

Really? You can't just talk to the person and gauge their enthusiasm? I talk to devs all the time and they typically wear their tech bias on their sleeves. You know who is hard core C# and wouldn't touch java w/ a ten foot usb cord after just a few moments.