You've probably already heard of China's Didi Chuxing. It's the ride-hailing firm best known for driving Uber off China's streets.

It is now also the world's largest ride-hailing app, and with its worth currently at $56bn (£39.4bn), it is also the world's most valuable start-up.

But how much do you know about its enigmatic, low-key founder, Cheng Wei?

Well for a start, he's only 35 years old.

"I was born in 1983," he tells me as we walk around the massive Didi complex on a chilly Beijing morning.

It is his first TV interview with foreign media.

"My entire management team has a lot of people in their 30s," he says. "We are idealistic and can be rash sometimes, but we also bring a lot of surprises."

No-one could accuse Cheng Wei of being rash. Every step of the Didi journey has been well planned.

His first step was to rule the market in China.

His next step, he tells me, is to take over the world: "The Chinese market is of course very important, but today Didi's vision is already going global."

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But Cheng Wei is quick to point out that Didi's way of entering new markets is not what most in the West may be used to.

"Didi's global strategy may be a little different from others," he says, smiling. "Our strategy isn't always to do everything ourselves."

"But in markets where there aren't any successful local companies, then Didi will enter that market to share our experience. That's what we're doing right now."

Global market moves

Precisely and methodically, Didi is making its move into global markets.

It has already entered Japan and Taiwan. And earlier this year, it acquired 99, Brazil's leading ride-hailing app.

Just this week, the company told the BBC it was also launching in Mexico. The move will set it up to compete against its old American nemesis - Uber - right in that firm's own backyard.

But expanding internationally for Didi may not be all that easy, simply because of the suspicions Chinese companies sometimes face when they try to go overseas.