Depends how long you've done it, and how much the landscape has changed since then. I can still hop back into SQL and it all comes back to me though I haven't done it regularly at all for nearly 10 years.

In the web front-end world I'd be pretty much a newbie. I don't know any of the modern frameworks, everything I've used is legacy and obsolete today. I'd ramp up quicker than a new junior because I understand all the concepts of HTTP and how the web works, but I don't know any of the modern tooling.

How much do you think Linus Torvalds has coded over the last decade? Why is he still able to do his job?