An ex-Facebook and ex-Google software engineer conducts one of the toughest coding interviews with a high school student.
And didn't expect him to pass... with flying colours.
Clément Mihailescu conducted a mock Google coding interview with high school student William Lin.
Advert
Despite it being a mock interview, it's a true test used by the tech giant and Clément has used it with his many previous candidates.
'This is exactly the type of coding interview that you would get at Google or any other big tech company,' he stated separately below his video.
They use all the same methods as well including screen sharing, video calls and a shared Google Docs sheet.
But, William Lin isn't just your average high-schooler.
He's a talented competitive programmer who won Google Kickstart Round A and represented the US at the International Olympian of Informatics where he came second.
'For this Google coding interview, I asked him the hardest question that we have on Algo Expert called Airport Connections,' Clément added.
Advert
William had 45 minutes to solve the problem.
In the scenario, William was an airline operator with a list of airports. Each airport was represented by three-letter codes as they are in real life, like BUD (Budapest) and MAN (Manchester).
'You want to make sure that any traveller who wants to travel to one of these airports starting at your headquarters can do that,' Clément told him. 'You want them [passengers] to be able to reach any airport in your list of airports.'
William needed to create a function or algorithm to determine the minimum number of routes or connections required for his passengers.
Advert
And safe to say that the interviewer was blown away by his performance throughout. His coding and explanation were to a T, finishing in a couple of minutes over the time limit.
Clément added: 'It was absolutely insane, really incredible performance. The fact that William is so young just adds even more impressiveness to all of this.'
Commenting on how he expected the interview to go, Clément said: 'This is the kind of question I would never expect a candidate to be able to fully solve and fully code out in just 45 minutes.
Advert
'I would expect them to struggle through it, to maybe get a potential solution code out some of it.
'I would certainly expect to give them a lot of hints.'
The YouTube community was also amazed by William's programming speed and talent.
'Imagine you have to present your project in class just after this guy,' one wrote.
Advert
'He’s making my parents proud,' another chimed in.
'Non programmers don't realize how impressive this is. Most software engineers can't solve this,' replied another.