> but I’d probably utterly fail any type of formal interview where they asked me to write or explain code on the spot.
If you've gotten any sort of software project to work the way you wanted it to, which it sounds like you have, I doubt this quote is true. Any company worth working for is more interested in hearing/watching you break down problems into pieces and describe how to solve them. Often times this can be done in 'pseudo-code'. If interviewers are going to nitpick your code for trivial syntax issues (i.e. things that can be fixed with 10-seconds of google-fu), there's a good chance you won't want to work for that company anyway.
If you've gotten any sort of software project to work the way you wanted it to, which it sounds like you have, I doubt this quote is true. Any company worth working for is more interested in hearing/watching you break down problems into pieces and describe how to solve them. Often times this can be done in 'pseudo-code'. If interviewers are going to nitpick your code for trivial syntax issues (i.e. things that can be fixed with 10-seconds of google-fu), there's a good chance you won't want to work for that company anyway.