I had a long life as a consultant / contractor in the US and UK. Always chose the better money for what I knew than less money for to get experience in new technologies.
In my thirties, went back to Uni for an MBA. Pretty much the kiss of death for tech positions.
Did pursue new tech on my own time but they are a very tough to sell to employers.
Employers will always take the kid out of school over the old hand. They are cheaper, much more likely to do what they are told (regardless of whether it is right or not) and regardless of whether they know what they are doing. (Um, that's how we all got started, right??)
Ended up doing databases for marketing companies (talk about going back to the Stone Age) and rode that for a while.
Am now basically retired (on the corporate scrap heap).
So, lessons for you cocksure young 'uns?
1) Don't grow old.
2) Never miss an opportunity to add content to your CV, collect acronyms as if they were gollie badges (or Pokémon cards, if that’s your thing).
3) Always, without fail, whenever you leave a gig or project, put everything in your CV. You can always cook it down later.
4) Get physical reference letters from you bosses and coworkers. Get them signed, yes sonny, on paper; even if it means printing linked-in endorsements and bringing it to them with a pen. Make scanned copies available. Bring the originals to interviews.
5) Actively solicit Linked-In connections and endorsements. If you are too shy to this, you are in the wrong line of work.
6) Don’t grow old; and if you must, don’t show it.
If I had my time again, I would never leave tech (you can never return from the Dark Side), and would have kept the tech skills sharp. I ended up in senior non-tech positions. Management is a thankless treadmill where you work a lot of unpaid hours, you will lose your personal life and lose your perspective. When the company spits you out and you recover your free time, it is like waking up from sleep walking.
Sorry for the rant, I could write volumes.