I'm right there with you. 39 years old and I've been doing Linux systems administration and writing code since college in the mid 90s. Aced every interview I ever went to up until a couple of years ago. These Google-style coding interviews for systems/operations roles are the death of me and it's a shame. I have deep systems experience and I spend a lot of my spare time coding in Go [1] but I have little formal CS education and my full-time gig does not involve writing code all day, errrr' day. It's so frustrating, these interviews. You want to tell them, "Look, hire me and I will make your infrastructure scaling issues disappear and I'll save you money doing it" but that never happens because they see me get hung up on a sorting algorithm and immediately lose interest.
I'm not looking for a new gig but I'll give their site a shot when I am.
Pragmatically, why don't you spend a couple dozen hours drilling typically interview questions? It's easy enough to learn enough about, say, sorting in a few hours to pass most interview questions about it.
I'm not looking for a new gig but I'll give their site a shot when I am.
[1] https://github.com/chrissnell?tab=repositories