I'm a "senior" (I was 55 when I started looking), and I didn't have a "network," because I was a manager, and wanted to get back into technical stuff (I'm
very good at technical stuff, but I was paid to manage). I had a network of pretty heavy-duty people, but they all knew me as a manager, and I didn't want to put them on the spot for technical stuff, since that wasn't how they knew me.
That basically meant that I had to come in the front door to places I was interested in.
I was a bit "picky," because I wanted to do stuff that interested me. I didn't really care about making a lot of money, or beanbag chairs, or whatnot. I wanted to do work that engaged me.
I'm a very experienced Apple native developer, and I'm good at writing stuff that talks to other stuff (like client/server systems, device control, realtime video, etc.). I'm good at writing APIs and SDKs. Making devices sit up and beg is something I've always enjoyed.
So places that did stuff like that, interested me.
In my experience, I was treated like absolute crap. After a few rounds of "interviews" (which seemed to be opportunities for relatively young engineers and managers to patronize and condescend me), I just said "bugger this for a lark," and decided that I was retired. I set up a small company, so I could buy toys, and started following my own muse. I found some folks doing non-profit stuff, that couldn't afford people of my caliber, and started working with them, for free.
It was the best decision I've ever made. In the last five years, I've probably done more work than I did in two decades previously, I've learned more, every day, than I have, since my twenties.
[UPDATED TO ADD] If you want "senior" people, they are likely to come with a rather fetching shade of grey to their well-coiffed pompadours, and I'd suggest that it would be rather self-destructive to treat them badly. There seems to be considerable resentment towards us older folks. I'm not one to judge whether or not it is merited (in my case, it is definitely not), but it may interfere with efforts to recruit more experienced folks.