Since the 1980s, the city has seen a fresh flowering of cafes and Western-style restaurants. There used to be at least two dozen cafes on the central section of Nanjing Road, a shopping Mecca that spans about 3 kilometers.
"I've been to every one of them," said Zhu, who said his hobby is "cafe-hopping". Unlike the aggressively expanding Western coffee chains, State-run Deda is one of a kind.
Founded in 1897 as the Cosmopolitan Cafe, it has built its reputation on serving authentic German cuisine. It was renamed Deda (meaning German feast) after the People's Republic of China was founded in 1949.
"It's hard to tell whether it is the cafe that sustains the tradition, or our regulars that keep us going strong," said Huang Jianying, one of the cafe's managers.
She began waitressing at this quite male-dominated milieu three decades ago, right from school.
Referring to Hua Mulan, the legendary female warrior who pretended to be a man in order to fight on the battlefield in ancient China, she said: "I am the Hua Mulan of the coffee world".
About 100 regulars aged 50 to 92 pile in every day for their morning brew, she said, adding "we tend to lose one or two each year, for obvious reasons".
Other waitresses claim the shop uses Italian coffee beans grown in China's Yunnan province, where Starbucks also sources its coffee beans for its China outlets. No menu is offered in the morning. It's either an Americano, or go thirsty.
The boiling beverage is served in a small yellow porcelain cup with a disposable plastic spoon and sugar bags. A can of evaporated milk from Nestle does the rounds for those who need milk, or something like it.
"Smoking and food from outside is prohibited during our regular business hours, but we make exceptions for these guys in the morning because they have formed these habits over decades," Huang said.
For some, the cup of coffee is akin to an entrance ticket. They buy it so they can socialize and chat with friends.
When they are done, they are more likely to switch to green tea and munch on steamed buns and crispy fried bread sticks.
"The first two-thirds of the coffee are for enjoying. The rest qualifies us to stay," said Shen. "When I'm done, I fill the cup with water and use it to swallow my pills－so it really is delaying my march to the grave."