[ams6110]

It's still not realistic. People don't code on whiteboards. You code (today) with all the resources of the internet at your fingertips, and if you need to invert a binary tree you will use a well-tested implementation from a standard library.

[TheCoelacanth]

It's not supposed to realistic. It's supposed to be a test of programming ability that fits into an hour interview with time left over for talking about other things. Real world projects last months or years. You can't fit that into an hour, so you have to make do with something that can.

[LamaOfRuin]

Which is why they're not asking you to do it in an actual job. It's a proxy problem that is easy to communicate so you're not spending the entire interview explaining the problem. Arguably, fleshing out a spec would also be a valuable test, but not the same one.

[kuschku]

People often do code on Whiteboards – but not actual code, but diagrams, plans, etc.

[catnaroek]

Sometimes actual code too. For instance, if I'm designing an optimization pass for a compiler, I'll write toy IR programs and show how the optimization pass will rewrite them. And I'll do it on a whiteboard.

[kuschku]

Yup. But the thing I meant is that you illustrate things, not actually code your application code.

[catnaroek]

I know for damn sure that, if I'm implementing something algorithmically tricky (not BFS, though), I first sketch the details on a whiteboard or a piece of paper.