>>"Back when I was at Google, I was most­ly in­ter­view­ing peo­ple for “Developer Advocate” po­si­tion­s, and a lot of peo­ple some­how got in­to the pro­cess with­out be­ing able to code at al­l. So, ear­ly on, I’d ask. “You’ve got a list of ob­ject­s, write some code to se­lect one of them at ran­dom. Any lan­guage, don’t wor­ry about syn­tax, as­sume the built-in ran­dom func­tion is good enough.”

That was ac­tu­al­ly a nice ques­tion: If you want­ed to dive a lit­tle deep­er, you could ask the can­di­date to sketch in unit test­s. And if you’re talk­ing to some­body super-technical, ask “Your code is in pro­duc­tion and some­times it’s throw­ing illegal-index ex­cep­tions un­der heavy load. What’s go­ing on and how do you fix it?” Just be­cause that’s a cool prob­lem, very real-life, and most peo­ple smile when they get it."

Genuinely curious as to what the reasons for illegal-index exceptions under heavy load would be? I genuinely can't think of any reason. Perhaps the problem is under specified. Unit-testing would need to be seeded to be reproducible.