Generally, every percentage point of GDP growth will add 1.2 million job vacancies to a particular region. As a result, the increasing economic vitality of China's smaller cities is adding to the demand for foreign executives.

"China's top 50 cities will account for 12 percent of global economic growth in the next 10 years, since they are already huge economic entities with total GDP of $2.9 trillion," says Kin Keung Fung, managing director of greater China for Jones Lang LaSalle Inc, a Chicago-based real estate investment services company.

In the past three years, China's main tier-two cities built almost 10 million square meters of new real estate for sale and 2.5 million square meters of A-grade office space, Jones Lang LaSalle said in its top 50 cities report, which was released in March.

The firm listed the top 50 cities in China based on their economic development, especially real estate construction data, and it described some cities as tier 1.5; that is, smaller cities that are developing into major cities.

Chengdu is a typical tier-1.5 city and more international corporations are developing their branches there.

As many as 173 of the world's top 500 corporations had branches in the city at the end of 2012. During the first nine months of last year, more than 20 global top 500 corporations established branches in Chengdu, according to the 2013 white paper from the American Chamber of Commerce in China.

"Although foreign direct investment in China fell by 3.4 percent from January to August 2012, Chengdu managed to achieve an impressive increase of $5.568 billion in realized foreign investment, a rise of 20.62 percent compared to 2011," the white paper says. Manufacturing and service industries attracted the most investment.

The rapid growth of these smaller cities has not only surprised the expats living there but has also given them confidence to continue working there.

"We could not imagine the speed of growth before we came to China," says Bukenberger, who had previously lived in Singapore for four years.

Many Chinese cities have tried to become more international by attracting global brands to their markets, and this has also attracted expats.

Kempinski Hotels, the European luxury hotel management group, opened its 18th hotel on the Chinese mainland in Yixing, Jiangsu province, which is a tier-three city.

Sebastien Mariette, general manager of Kempinski hotels in Wuxi and Yixing, Jiangsu province, was sent to set up the new hotel a year ago as part of the company's campaign to establish a presence in China's lesser-known cities.

The local government's support helped the hotel chain establish itself in Yixing, although so far 99 percent of guests at the hotel have been Chinese.

"For the city's international image, the local government wants a high-end international hotel here," Mariette says.

But in Wuxi, Mariette has seen expats attracted to the city.

"Over 50 percent of my guests in Wuxi are laowai (expats)," he says, as there are many foreign companies and factories in the city.

The expat community in Wuxi, which is near Shanghai, is also growing, he says.

Before working in Jiangsu province, Mariette was assigned from Africa to set up a Kempinski hotel in Huizhou, Guangzhou province.

"My experience in building up new hotels may be a reason for my company sending me to cities in China," the 37-year old Frenchman says.

Mariette is the only foreigner working at the hotel in Wuxi, because the Chinese employees can quickly adapt to the group's European standards, he says.

"But we still need a general manager from Europe," Mariette says, as that person needs to ensure the hotel maintains the company's European style and standards.

Mariette says he prefers the smaller cities because they have more Chinese character than the big cities.

"Big cities like Shanghai and Beijing are pretty much the same as other international cities, like New York or Paris," he says. "But the smaller cities are very Chinese."

The bright future of local development is another main reason why foreign senior managers are moving to smaller cities.

"As the government and companies are exploring the markets in smaller cities, the booming second and third-tier markets promise better career development," says Robert Parkinson, CEO of RMG Selection, a British executive search company specializing in recruitment in Asia.