Part-time pursuits for tertiary students in the past might have included giving tuition or working at coffee joints. However, in the last few years, a new option has emerged - driving for private-hire car services such as Uber and Grab.
While taxi drivers must be at least 30 years old, under new regulations announced in April, there are no age restrictions on drivers for private-hire car services.
Uber previously had an age limit of 25 for its drivers, while GrabCar drivers had to be at least 22 for those with their own cars and at least 23 if they rented the cars.
Under new Grab and Uber policies, drivers for both services can now be as young as 21.
Private-hire drivers, who are believed to number between 6,000 and 8,000 here, are required to have held a class 3 or 3A licence for at least two years.
Uber said 25 per cent of its drivers are under 30, while a spokesman for Grab declined to give numbers but said it does not have a large proportion of drivers below 30.
"Those under 30 usually drive part-time with us to supplement their household income and to gain some financial freedom," said Grab's spokesman.
Uber drivers and friends Gurujeet Singh Sanghar, 23, and Nur Afiq Jumahat, 22, said about five of their friends are currently working as private-hire drivers, while at least five more are interested.
Mr Nur Afiq hopes to get a scholarship to pursue a diploma in broadcast media from the Lasalle College of the Arts, while Mr Sanghar has been accepted by the Singapore Institute of Technology to pursue a degree in chemical engineering.
They were drawn by the potential to earn while working flexible hours, and say they are each able to make about $700 a week.
"I was looking for a less taxing job, where I could work my own hours and have the convenience of having a car," said Mr Sanghar, who started driving in April after leaving his job as a production specialist in a perfume firm.
He said his father, a taxi driver, sometimes argues with him over the merits of driving a taxi instead of a private-hire car.
Mr Sanghar added: "He says cabbies need not pay 20 per cent of their fares to their companies and are not dependent on an app for customers."
For Singapore Management University law student Kenneth Chen, 26, he started driving with Uber in April. He bought a second-hand Honda CR-V to shuttle between home and school, and decided to use it to make some extra money.
"I thought it would be fun because I enjoy driving, but it's quite taxing," said the car enthusiast.
Mr Sanghar and Mr Nur Afiq said they do not see driving Uber cars as a career, and are doing so on a temporary basis while waiting to further their studies.
As for Mr Chen, he does not intend to be an Uber driver once he gets a full-time job.
But he said, in the long-run, he is considering using his car as a source of passive income by getting relief drivers - who might not have the resources to rent or buy their own vehicle - to drive his car while he takes a small percentage of their earnings from each trip.
"I think it's a good business model," he said.