Four decades ago, upon being designated as China's inaugural special economic zone (SEZ), Shenzhen had a mere 30,000 residents. Now that number represents one of Shenzhen's newer demographics: its permanent foreign resident population.

For Glenn Ball, an Australian entrepreneur who first set foot in Shenzhen in 2001, the numbers speak for themselves.

"From 30,000 people to almost 14 million (permanent residents) in just four decades, Shenzhen is a vibrant and developing city of the future in the making," Ball observed.

Only 3G phone signals were available when Ball first arrived, but by 2015, when Ball became the general manager of an online grocery service tailored to expatriates, 4G had become the norm, enabling him to run his business more efficiently.

"Now, Shenzhen leads the country to roll out full 5G coverage, which will further draw in global business," the 49-year-old entrepreneur said.

Realizing full 5G coverage is not the only first the city has marked. Shenzhen's pioneering spirit and many nation-leading breakthroughs also assisted Ball in his entrepreneurial endeavors.

"Shekou, being one of the first free trade pilot zones for importing ... really was a boon for business, and [they] are just some of the reasons why Shenzhen is such an innovative city."

The fact that Ball was even able to successfully run a business targeting the city's expatriates also speaks volumes about how internationalized Shenzhen has become in mere decades, thanks in part to its rising appeal for not just foreign businesses, but also international students.

"As an economist, Shenzhen was a very attractive place for me because it is a thriving city with an interesting and successful economic development story," said Carolina Mendoza from Colombia, explaining her choice to pursue postgraduate study at the Peking University HSBC Business School located in Shenzhen's Xili Town.

Through her studies, Mendoza witnessed first-hand Shenzhen's tremendous changes. "When I first arrived in the city, only one subway line from the Window of the World to Luohu existed. Now they have this elaborate transport system, with a full fleet of electric buses," Mendoza said.

After completing her master's degree in economics in 2013, Mendoza used Shenzhen as a springboard to find a job in Foshan, another city in the Guangdong-Hong Kong-Macao Greater Bay Area. She cites the pace at which Shenzhen grew around her as a form of motivation.

As the country's first SEZ, Shenzhen also boasts a strong connection between the East and West, as attested by Fabiola Benitez, the Canadian co-founder of Global Friendship that connects Chinese people and expatriates.

"There is definitely a feeling of openness in Shenzhen," she told Xinhua. "As soon as you arrive in the city, you can feel the modernization that it offers, which extends to our members and business partners that we have been able to connect and organize events with."

Benitez is particularly impressed by the city's infrastructure and transport system, telling Xinhua that when she first arrived in the city in 2018, her first thoughts were: "Wow, this is what a new city looks like. When you compare the cities, you can really see the convenience of Shenzhen."

Ball and Mendoza also refer to the city as being open when sharing their thoughts on the southern metropolis, and 40 years on since Shenzhen became a "window" of China's reform and opening-up drive, these expatriates remain excited about what the city's future will hold for them.

"Shenzhen has been a huge part of my life and defined who I am. I also look forward to being able to contribute in my own way to Shenzhen's future," said Ball.