Re: should probably change job.
"Over 35 and not a manager in Tech? Don't get unemployed. They want people 3+ experience, working in a similar or more important company and don't want people over 40, except as managers."
I lost what I thought was a job for life when I was 57, and I had loved it there.
I was hired on at my current job at age 61, another job I love - but I was employed during all the preceding years, at times unhappily.
I am 65 now - which is normally retirement age - and have had HR of two large competitors contact me directly in the past month. Both firms knew my age, because the people who had them contact me, know me.
There is nothing special about me - I have just been extremely fortunate.
For what it is worth - my advice would be to always be prepared to leave your current position, voluntarily or otherwise.
Deliver what you promise and be respectful of your coworkers - don't be a source of the type of misery people are posting about here.
Maintain your current skills and cultivate new ones, because tech skills can have a short shelf life.
And for God's sake, if your job is miserable, your primary job should be working to move on to your next one. You can do it - even old farts can do it.