It's a lazy way to select the best developers assuming you have a lot of candidates. Often used by big companies who are recruiting for lots of positions. It's awful because it limits diversity and wrongly assumes good developers are good at performance coding.
βI notice that you have a decadeβs worth of contributions to open source projects on GitHub,β noted the recruiter, βthatβs great!β
βWhen would be an ideal time to schedule you for your whiteboard coding exercise?β