I find people are quite reasonable in real life. Unlike the internet, they're not going to bite your head off.
Next time it happens, tell the truth.
"Oh, hey guys, I get really, really nervous about whiteboard coding. It's really scary for me and right now I feel like my brain has stopped and I'm going to fail miserably. Would it be OK if we do this another way? - maybe on a computer, or maybe I can just talk about it?"
If you need it, you can also say "Can I please have a 5 minute break to get my head straight? Maybe a quick walk to the bathroom and a glass of water?"
I would be utterly and completely shocked if a rational, intelligent human being denied you that. And if they did, would you want to be working for/with them anyway?
Only issue with this is that those interviewing you might not be who are hiring you or you would be working for. So maybe their lame, but your actual day to day or your actual boss are awesome. Though it's on the company for not providing a good interview experience.
Next time it happens, tell the truth.
"Oh, hey guys, I get really, really nervous about whiteboard coding. It's really scary for me and right now I feel like my brain has stopped and I'm going to fail miserably. Would it be OK if we do this another way? - maybe on a computer, or maybe I can just talk about it?"
If you need it, you can also say "Can I please have a 5 minute break to get my head straight? Maybe a quick walk to the bathroom and a glass of water?"
I would be utterly and completely shocked if a rational, intelligent human being denied you that. And if they did, would you want to be working for/with them anyway?