When he went to the United States to attend the Apple Worldwide Developers Conference (WWDC) in California, Yuma Soerianto just wanted to learn more about coding. But when the 10-year-old returned to Australia, he'd been praised by Apple's CEO Tim Cook, met Michelle Obama and been interviewed by the international media.
The WWDC is used by Apple to showcase its new software and technology for software developers.
Yuma was the youngest coder in attendance. The fifth grader from Middle Park Primary School in Melbourne went to the event with his dad Hendri and his mum Dollies.
On the eve of the formal conference, Yuma impressed Tim Cook with an app that Yuma had made during the flight from Australia to the US.
The app was designed to help his parents with their souvenir shopping, by adding the local sales tax and converting the currency.
"Very cool. That's great," Cook told Yuma after seeing a demo of his app.
"You can make an app in one hour. I'm impressed. I can't wait to see what you do next."
"There were many interviews from all over the world," says Hendri.
Yuma's family are originally from Indonesia.
"We've been in Australia for almost eight years, I'm originally from Jakarta. We lived in Singapore before this, and Yuma was born there. We moved to Australia when he was three," Hendri explains.
Yuma started learning code when he was six because he said schoolwork was not a big enough challenge.
He created his first app just last year and now has five apps in the App Store.
Yuma uses the programming language Swift, which he learnt by doing an online course offered by Stanford University.
"WWDC was awesome. The new technologies were just amazing, and for the first time, I got to get professional help from people I can talk to," Yuma says.
"I only learned online since no schools could teach me coding.
"The people I met were really special! I met the top Apple people and of course Tim Cook, CEO of Apple. I also got to talk to Michelle Obama."
Yuma now has his own YouTube channel, Anyone Can Code, as he wants to help other people learn how to code.
"It is his passion to teach others coding. It would be good to inspire Indonesians to learn to code too," says Hendri.
Yuma has big plans for the future.
"I want to make app to revolutionise the world. Also, I want to teach the other kids on how to code. That's why I made the YouTube channel Anyone Can Code, for other kids to learn.
"But I found out later, actually my channel has been watched by adults, who learn from me," Yuma told the ABC's RN Drive program.
This story is also available in Indonesian.