Guangdong, with 126 million people, topped the table for provincial population size according to the latest national census.

Many of those people live in the nine cities on the Chinese mainland that are part of the Guangdong-Hong Kong-Macao Greater Bay Area, a megalopolis that stretches across the Pearl River Delta.

The Bay Area, encompassing nine cities in Guangdong plus Hong Kong and Macao, was home to over 72 million people last year.

The Outline Development Plan for the Bay Area, released in 2019, said the main goal was to further promote integration between the cities and make the mainland part an attractive career destination for ambitious young talent from the two special administrative regions.

Ma Xingrui, governor of Guangdong, said the mainland part of the Bay Area now has nearly 600 entrepreneurial teams of young people from Hong Kong and Macao, plus more than 4,000 employees from the two regions in various professions.

Stephen Zhang, a young lawyer from Macao, is one of 60 Macao residents to have passed the National Bar Examination. He decided to work for a law firm in Zhuhai.

"Decades ago, people in Macao preferred to work and live in Western countries, but things are changing," he said. "We've found we can play a unique role on the mainland."

The firm he works for is the first joint-venture company formed by law firms from the Chinese mainland and the special administrative regions, and it was looking for candidates with diverse backgrounds.

"Because Stephen completed a master's degree in law at National Taiwan University, and is a Macao native who was admitted to the bar, we gave him an offer," said Lei Wun-kong, a senior partner at the firm.

To address a major concern about taxation differences in the Bay Area, the mainland cities invested over 2.3 billion yuan ($370 million) to bridge the gap and guarantee that employees can enjoy the same low personal income tax rates as in the special administrative regions.

According to the development outline, the Bay Area will become a prestigious city cluster with innovation as its top economic engine before 2035.

The Bay Area is already home to some of the world's most innovative and influential companies, including internet giant Tencent and world-leading drone manufacturer DJI.

But instead of working for the big names, Poon Hun-fai, who hails from Hong Kong, started his own business in the Bay Area after earning a doctorate in biochemistry from the University of Kentucky in the United States.

He runs a startup biotechnology company in Zhongshan that has grown from three employees two years ago to over 120. Its original 900-square-meter research and development laboratory has expanded to over 10,000 sq m.

"The rapid growth of the biomedical industry on the mainland is beyond my imagination, and my confidence in startups came from the plan, which stresses the government supporting the city in promoting innovative biomedical development," Poon said.

Hong Kong Chief Executive Carrie Lam Cheng Yuet-ngor told a youth forum on May 6 that the Hong Kong Special Administrative Region government had launched a youth employment program in the Bay Area to encourage more Hong Kong university graduates to explore futures on the mainland.

"As of April 30, there were 321 companies associated with the program offering 2,394 jobs, which is higher than our expectation of 2,000, and 1,267 of them were in innovative positions, nearly double our estimate," she said.

Unlike other bay areas around the globe, Ma said the Guangdong-Hong Kong-Macao Greater Bay Area is shaped by the "one country, two systems" principle and comprises three separate customs territories.

Despite those differences, the people living in the Bay Area have a lot more in common.

Ricky Woo, a 25-year-old from Hong Kong who works for an insurance company in Shenzhen, said many of his colleagues from the mainland share his memories of famous Hong Kong movies, and many have become good friends.

In addition to the relatively low cost of living on the mainland, Woo said the cuisine was one of the main reasons he chose Shenzhen when he embarked upon his career in 2019.

"I've never felt homesick, and it is not only because of the convenient transportation that allows me to get home within an hour, but also the food served in the restaurants under my apartment is the same as in Hong Kong," he said.