I wish I could be so lucky to attract senior candidates at my current gig; they're hard to come by at a trendy downtown-SF mobile commerce pre-series-A startup. Instead, I'm inundated with fresh code-bootcamp graduates. I'd be much more comfortable hiring those junior developers if I knew they would be able to sit next to a reliable senior teammate...
That said, if you're worried about being hired, start by building something on your own! You'll make yourself much more marketable if you show that you can pick up new technologies and actually release something.
One suggestion: don't worry about dating yourself by talking about old tech you once worked on. For some reason the older developers I've worked with take a while to getting around to telling you about the time they wrote LISP in Genera on a Symbolics 3640 for cutting edge CAD/CAM/simulation tools at Boeing in the mid 80s or whatever (such cred!).
Senior engineers with experience are hard as hell to come by. They offer perspective and focus: something that is often needed but hard to find.