>I was handed a hardcopy of the MPEG-2 transport stream spec and told to read it and come back with questions.

OK, but what did you have to do on the job with the spec after reading it? Did you also have to do a codec implementation in SW or what? Don't leave us hanging.

>That's how you onboard.

Yeah, 15-30 years ago, when professional experienced SW devs weren't dime a dozen. Valve would also hire people off the street who never wrote any SW to code on the original Half-Life. But those days are long gone now, after 10+ years of "just learn to code bro" and ZIRP creating an oversupply of coders who now need to know a dozen programing languages, frameworks and buzzwords just to get a AI written rejection. Those were the days, writing SW felt like a craft, a science and a hobby at the same time.

But alas, certain jobs in EE/embedded SW still work like this. You get to read and learn a lot of source code, requirements, specs, design documents and standards, before actually building things, plus a proper (graybeard) mentor to onboard you. At least those remaining jobs that haven't yet been offshored(defense, aerospace).