If the toaster had a shade selector, a built in camera and was factory color calibrated, then no matter what I stuck in the toaster it would come out that color (or hit some global MAX_TOASTING_TIME) .
Good software engineers design robustly without increasing the problem domain (much).
Simply hook your control logic to measures of radiant heat, rather than time.
Thankfully, I inherited my grandmother's 1960s Sunbeam toaster , which still makes perfect toast to this day.
It's nice to have things from before we unlearned how to make them.
 This one, specifically: https://www.ebay.com/itm/Sunbeam-Vista-Radiant-Temperature-C...
* Twee nostalgia for technology of yester-year annoys me; I feel the same way about people who preach about the technical superiority of safety razors and vinyl records.
As for the body, I can report that as of this morning it's within the thermal range of a full-load MBP.
I see the shock hazard as a learning opportunity. Maybe I'm old fashioned, but "Don't stick fingers / metal objects into the internals of electrical devices" seems like solid life wisdom.
Thankfully, I was shielded from the price, but quality costs money. In return, you get a lifetime (or more) of service. You may optimize differently.
And as a final note, there is no toast "ejection." To do so with such violence would be crass and disruptive to my morning calm.
My toast instead gently and incrementally rises to a comfortable removal height, while a chorus of angels sings in the background. Truly an elegant toast maker, from a more civilized age. /Twee
PS: I'm also happy to wax on the benefits of my daily driver 1940s Gillette Super Speed safety razor.
Who wants a toaster that can't handle thick cut bread or bagels in the 21st century?
And it's not just California. You couldn't get UL approval for such a toaster today, so it would not be sold anywhere.
These old toasters cost the equivalent of $235 in today's dollars. (~$23 in 1949) Of course if you buy a $200 toaster today, it would be a marvel of technology. Nobody buys $200 toasters though, you can get a crappy one for $15 and that's what people buy, so any comparisons between today and yesterday are unfair. Compare like price with like price.
I don't think they have the features of the Sunbeam though. If there is a model that does, I'd like to know about it since it sounds brilliant.
...which would fail on dark breads like pumpernickel or be confused by marbled or cinnamon swirl breads.
I think this points out the challenges of "Just make me a simple X" that business and product folks always initiate with, hoping to get the cheapest solution.
Then they wonder why it fails in every way except the ones they explicitly said during design/coding and why there is a long tail of updates that often exceed the MVP...
Off with his head!
A four-bit microcontroller, or physical integrator, can evaluate radiative doneness much more reliably than a camera.
If I don't know the proper time in the microwave to heat a dish, I just let it run until it starts to smell right. The same strategy should work for toast.
This is a pretty cool toaster:
Who needs bimetallic anything when you have gas and fire. Keep it simple right?
For example, I had a physics problem and a computer science buddy was opposed to solving it ourselves. He insisted we needed an expert. When at worst it needed differential equations that ended up cancelling out. It wasn't a hard problem, it just took some effort.
Is this a rare experience? Or have other people found a reluctance of math in comp sci?
Today, computer science at my old school is part of liberal arts and differential equations isn’t listed anywhere on the curriculum.
Because many aren’t taught differential equations it’s hard to know what they can do, or how to use them so it’s easier to just get an expert.
I have not been able to discover which of those a Computer Science graduate is. By observation, a piler-on of frameworks, most usually. But some scientists and some engineers get CS certification, so you can't be sure, by the label.
1. microwave ovens became affordable, popular, and then discovered to be terrible for browning things, but so good at generally warming food that they became a smash hit.
2. toaster ovens were introduced, with two hardware controls instead of one (heat and time), which did an acceptable job of toasting but also handled lots of other small warming and browning tasks.
3. toasters came back as a nostalgic luxury good.
In all of these markets, the companies with more robust hardware capabilities were able to charge a premium, attract customer loyalty to their brands, and use the brand reputation to diversify to related kitchen goods.
Mark Twain wrote, "An engineer is a [person] who can do for a dime what any damn fool can do for a dollar." Adjusting for inflation, the engineer can do for a million dollars what any damn fool can do for a billion.