Mr Harre has been in F1 for 11 years now and loving every minute of it.
He was born in South Africa but the family shifted to New Zealand when his secondary school finished. He earned a mechanical engineering degree from Auckland University. An aspiration to be involved in motorsport is one thing but getting there is no easy task.
"Putting your name forward for a job puts you up against hundreds of others, so it's not easy," he said. "You might have the qualification but you don't have the experience and that's what F1 teams want."
Mr Harre starting off working in carbon composites, building show cars which replicated race cars. A couple of years later he was involved in the A1 Grand Prix series (New Zealand had a team running in it), and then came time with Super Aguri team in F1 in 2005-06.
The team wanted mechanics but when they saw his degree he was pushed further up the food chain and he was soon working data analysis, poring over figures coming from the race car's telemetry.
"I was a bit intimidated at first. They were offering me twice the salary I was then earning and I thought, what the hell have I got myself in for."
That team was run as a seat-of-the-pants operation but it gave Mr Harre excellent all round grounding.
As he climbed the team tree he had responsibility for more mechanics - from handling data he was handling all aspects of the car's performance, involving fuel, brakes, suspension, stuff that's super critical to car's performance.
The team pulled out of F1 but he got a job testing engines with McLaren. It was also 2008, the global financial crisis was biting and manufacturers were cutting back, which affected contractors like Mr Harre.
But the Virgin team was just starting up and he found work there.
"F1 ventures just starting are a nightmare, doing things on limited budgets with a third of the people normal teams operate on. The first year was tough. People put in huge hours to get things sorted out," he said.
In 2010 he had an option to go to Red Bull but Virgin offered him a spot as race engineer for Timo Glock in the 2011 season.
"Running 20 odd people on the track and keeping the car running is a huge learning curve. But Timo was a really talented driver and fun to work with."
In 2013 he was working on the 2014 engines the F1 cars would be running and come 2014 he was working with Williams as a performance engineer.
Then, at the end of 2014, Mercedes-Benz came calling, offering him the job of chief trackside engineer. It's a position he's still in. He's the man who manages the crews and drivers for the team at the track which also means he's managing the egos of two different drivers with the same ambition.
"One is very naturally gifted (Hamilton) and the other (Rosberg) is very technically capable and pushes us a lot. I can't be biased but if the drivers come to me with issues I'm the one who has to mediate.
"At Mercedes, we want to win the constructors' championship. In terms of the drivers' championship we also want to finish one-two but it doesn't matter to us who is first and who is second," he said.
Mr Harre has a couple of weeks respite with his parents before heading home for more testing in and working up for the 2016 season starting in April.
When he has the time he races a BMW E30 in Britain and when he's back in New Zealand he dusts off a Ford Escort Mk 1 2000 that he's run at Pukekohe and Hampton Downs. This weekend he and his dad are taking it to Manfeild for a run.
