They're mostly poor villagers from the Indian state of Maharashtra.
But the dabbawalas have become an entrepreneurial sensation covered by the world's most famous business magazines and feted by Prince Charles.
That's because these 5,000 semiliterate small businessmen have figured out how to deliver 200,000 hot home-cooked lunches to offices around Mumbai each day with a 99.9999 success rate, according to spokesperson Subodh Sangle.
"We have kept the cost very low for the service," Sangle tells the Straight on the phone from Mumbai. "We sell from the security guard to the highest official."
Indian management guru Pawan Agrawal wrote his doctoral thesis on the dabbawalas in 2001. Through many inspirational speaking engagements, Agrawal has helped make the dabbawalas famous around the world.
But their biggest jolt of publicity probably came in 2003 when they were visited by Prince Charles.
"We got an invitation, as you know, to his marriage," Sangle says. "In between, we have been getting letters from him when there were heavy rains in Mumbai. Also recently when he became a grandfather, there was an exchange of letters again."
In 2011, Forbes magazine featured the dabbawalas in an article about innovation in India.
Sangle reveals that most of the dabbawalas are followers of Lord Vitthala, which is a manifestation of the Hindu god Vishnu.
Formed 125 years ago when a banker wanted home-cooked meals, the dabbawalas' system relies on colour coding and numeric characters that can be understood by the workforce.
"They pick up by hand [from the home]," Sangle says. "If the distance is short, they walk it up. If it's quite long, they'll take it on bicycles."
And if the hot lunches need to be taken across the city, they're transported on local trains. Sangle says the dabbawalas are not using the Metro, which recently opened in Mumbai.
The average monthly cost is 400 rupees, which works out to just over $7.
"What happens is a dabbawala from an area gets connected to the other dabbawalas in that particular area, and they form a group," Sangle says.
He mentions that depending on which group they belong to, they will earn anywhere from 8,000 to 15,000 rupees ($142 to $266) per month. Each group divides the money equally.
A group in the suburbs, for instance, has a system for connecting to another group in South Mumbai, where many offices are located. An association ensures there are standardized rules across the city.
Sangle explains that the system generates additional income through advertising. Pamphlets are inserted into the lunch packages, reaching 200,000 people per day.
"I handle the p.r. and also coordinate for some advertisements," he says.
There's also a program allowing visitors to Mumbai to spend a day with the dabbawalas. One of the most famous people who did this was British businessman Richard Branson, who delivered lunch to his Virgin office in the city.
"They can get a chance to travel along with the dabbawalas from the pickup to the delivery to the customers," Sangle says. "And then they have a lunch with the dabbawalas."
Follow Charlie Smith on Twitter @csmithstraight.