It was a lousy job, but OFs can't always pick and choose, so I "gritted my teeth" & stayed, until I couldn't stand it any more.
You described exactly the situation that made me break myself (burnout, depression) -- except I was the young whippersnapper (22-30 years old) with the actual knowledge (both real-world and theoretical -- I just happened to be in the right place at the right time for that), and the results to prove it; but not the real-world experience to deal with social games playing administrata and fake-it-till-they-make-it cow-orkers. Not knowing any better, I thought I was doing stuff wrong, and what they did was perfectly normal and okay.
At one time the boss of my department told me straight to my face that they simply couldn't trust me at all, because they had a son my age, who was completely useless. Apparently, I too must have been useless, because otherwise they would have had to question themselves as a parent and a teacher...
I was going to say that ageism seems to be applied from the middle out to the extremes of age, but on second thoughts, assumng they are unconsciously discriminating is giving them the benefit of the doubt.
Let's face it. they were just morons!
After a while, just as in your case, I began to question my worth--- you need a lot of confidence not to be influenced by constant disregard of your knowledge.
I could rant all day, but here are a couple of the dumb things they did.
The systems we were making translated OEM control signals into something the computer could use.
The prototype used plain old pots to do this, but all except one of the real controls used PWM.
Instead of converting these signals direct, they used the legacy design from the prototype, & fed the PWM
to RC integrating networks.
The resulting analog signal was then passed through an Op Amp, where its amplitude & dc component could be adjusted to place it into the middle of the transfer function of an ADC.
To do this, we looked at the ultimate readout on a monitor, whilst "tweaking" the appropriate pots.
It was nightmarish, chasing the thing all over the place, while peering at a PC monitor halfway across the room.
I suggested we set one up correctly that way, look at the level & centreing with an Oscilloscope, record that, then set the adjustments up that way.
It may not have been "spot on" but would have minimised adjustments done with the final display.
This was greeted with disdain.
OK, they didn't like that, so I thought I'd "lower my sights", & suggested they provide a small monitor on a
"wander lead", so we at least could do the adjustments their way without craning our necks to see what was happening on a screen across the room.
No joy on that one, either!
Another delight was a switch on which we had to painstakingly assemble a network of diodes, which was very difficult & time consuming.
No other switches, even though they used the same interface, had these diodes.
It seems that in the prototype, the "gifted amateurs" who designed it had anticipated a problem that the diodes were meant to fix.
When the problem didn't eventuate, they left them off all the other switches, but on the production units, they were slavishly reproduced on that particular switch.
I had a "win" on that one----I "buttonholed" one of the "real" EEs as he went past, & pointed it out to him.
The diodes were scrapped, but that was a "black mark" against me!
I better stop now, before I get too worked up, but there were many other things.
It seems that if there was a way to stuff something up, they would find it!