Ferrari : WhatsApp's Jan Koum and his Ferraris

Jan Koum has an Italian mistress. Her name is Ferrari. It was passion at first sight: she, a Ferrari 458 Speciale, he, the co-founder of WhatsApp. The romance quickly blossomed. So he bought another one. That was back in 2014.

Since then, hidden away in California's Silicon Valley, Koum's gleaming white two-storey personal garage - which currently hosts a dozen rare vehicles - has opened its arms to another two Speciale, plus a Ferrari F12berlinetta and a Ferrari F12tdf.

To say that Jan Koum likes Ferrari cars would be like describing WhatsApp as simply 'a successful tech company'; in reality the encrypted 'phone messaging service is reported to have been used to send around 63 billion messages last year by some 1.3 billion users in one hundred and eighty countries around the world.

After co-founding it in 2009, Jan Koum and Brian Acton, who'd teamed up together during Koum's near-decade as an infrastructure engineer at Yahoo, sold WhatsApp to Facebook for $19bn (Euro16.3bn) in 2014. That's when Koum's love affair with the Prancing Horse began. The 42 year-old Ukrainian-born tech entrepreneur, who moved to the United States with his mother at age sixteen, now laughs: 'I feel like Ferrari is my Italian mistress. When I drive (one of my Ferrari collection) I feel like I'm cheating on my other cars'.

What was it that first caught his fancy about that Speciale 458? 'As I drove (it) I realised that it was a very special car', he recalls. 'It's amazing for a naturally-aspirated engine to have that kind of performance and horsepower per litre. You just don't see it anywhere else. There's no other V8 like it'.

Upcoming changes to emissions rules meant V8 engines would be obliged to embrace turbocharging. So for Koum, missing out on one of the last naturally-aspirated high-revving mid-engined cars would have, he says demurely, 'felt like a mistake'.

It may have been the Speciale that first attracted his gaze but he is clearly enamoured of everything that the Prancing Horse marque represents. 'It's the racing history, the Italian engineering and all of the Italian passion that goes into the production of these cars that I find appealing,' he enthuses. 'They're exciting and fun to drive. And Ferrari is also a very unique, very special brand.'

Despite making his fortune in cutting edge communications technology, cars-wise Jan Koum is a traditionalist. Driverless technology is not for him. 'There are plenty of people who don't care about driving and just want to get from point A to B', he concedes. 'But there are plenty of other people like me who are passionate and enthusiastic about driving.'

For him, electric cars are also an unattractive turn-off. Feeling the engine start when he turns the key is an essential, almost sensual, experience. 'I've got to hear the sound of the engine and the note of the exhaust', he insists. 'I'm a little 'old school' in that regard'.

Koum may now be an extremely wealthy man, but he hasn't forgotten the poverty of his past. Dad, a construction manager, and mum, a housewife, raised him in a modest family home lacking hot water in a small village outside Kiev. Poverty blighted his early years in California too, when he and his mother needed welfare 'food stamps' to get by.

Tellingly, he chose to sign the Facebook deal leaning against the door of an abandoned building a few blocks from the WhatsApp headquarters. It was the former welfare office where he had once stood in line for those food stamps.

He says: 'I still have the same friends, and work, and personal life as before. I just have nicer toys now!'