It is easier to imagine, how transistors in the orders of 10s/100s are controlled by design, when they are all individually soldered/wired. The outcomes are predictable/known.

But, is it the same with microchips with billions of transistors? They are not individually soldered, and I would assume a small percentage of them don't work. How do these work? Are they programmed to work probabilistically? It's unfathomable how complex these are, but how the output from them are so controlled.

I am not from this field, and I have not studied about them more than what I was taught in school in my teens. A google search didn't bring up any helpful results, possibly because I didn't type in the right combination of words. All explanations of these are at the individual component level, -> a single transistor, 1s and 0s, and so on.

How are machine code written for these? Do they track and control the values of individual transistors? And, how is then the assembly language written to translate this to machine code?