It started out as a side project for a handful of enthusiasts who wanted to try building an app, but just five years on, the initiative has become a key growth driver for OCBC bank.
And today those four tech whizzes are the core of a much larger entity - known as the group operations and technology division - that is confronting big questions about what a bank of the future even looks like.
"It started very small, when four of us got together during the Christmas period and decided to build some simple apps for the company," recalls the senior vice-president of the division, Mr Praveen Raina.
"To be honest we didn't know how the apps would be received, but when we presented them to senior management, they were very encouraging, so we started getting serious about it and began building capabilities and growing the team."
Among the first apps that the group created was one to allow all OCBC employees to search for one another's contact details and photos on their mobile phones.
It was a hit with staff, who no longer had to be physically present in the office to look up the company directory.
Now that group of four working on apps in their free time has grown into a full-fledged team of 30 mobile developers that has rolled out a series of cutting-edge apps and enhancements to make life easier for OCBC customers and staff.
In May last year, the bank became the first in South-east Asia to launch an open API (application programming interface) platform.
This allows third-party software developers to integrate OCBC's APIs - lines of code used to build software and applications - into their own apps.
For example, a travel website has begun using OCBC's foreign exchange API for its customers to convert foreign currency-denominated prices to the Singapore dollar equivalent in real time when booking flights, hotels and travel packages.
In November last year, OCBC also became the first bank in South-east Asia to use blockchain technology in its local and cross-border payment funds transfer services, making them more secure and slashing the time needed to make such transfers from over a day to under five minutes.
The team has also made advancements on other fronts - using blockchain technology in fund transfers, using voice recognition technology to allow business customers to make banking transactions with Apple's Siri and most recently, using facial recognition technology to allow customers to access their banking apps.
Along the way it has hit some industry firsts, although that is not the ultimate aim, notes Mr Raina.
"We are not under pressure from management to always be the first to launch something. Nobody asks why we're not the first, if we aren't. But we do strive to be the first. Our philosophy is, if someone else could do it, then we should, too."
Complementing that is the philosophy that the team should not just pursue certain aims just for the sake of it; each milestone should have real benefits for the end user.
For example, the team worked on OneTouch, a service that lets mobile banking app users check their bank balances, latest transactions and credit card overview with their fingerprint on their smartphones, without having to log in.
"Before this, if a customer simply wanted to see their account balance, they would have to go through the whole rigmarole of logging in and going through two-factor authentication and all that," says Mr Raina.
"So we felt OneTouch would be a breakthrough, and we had to explain to the regulator how it would work, why we wanted to do it, how customers would benefit."
These days, Mr Raina is preoccupied with thoughts of what the bank of the future will look like, a notion that is shaping the projects his team is working on.
His vision is that data will be more important more than ever, with banks needing to know more about their customers beyond just their finances.
This would mean, for example, tying up with firms in different sectors to gain a "totality view" of the customer's life, so that each of those firms can offer that customer products and services throughout his life.
"It's all about building an ecosystem - we are working with organisations outside banking to see how we can leverage each other's capabilities to strengthen each other," he says.
Mr Raina cites an example: Say OCBC and its insurance unit Great Eastern were to tie up with a healthcare provider, a telco and a travel agency. With the customer's agreement, they could all share data.
So if the customer were to book a trip with the travel agency, the other four firms would immediately be notified. OCBC could alert the customer about relevant credit card promotions, while GE could offer travel insurance, the telco could provide an overseas data plan and the healthcare provider could suggest a health screening or vaccinations.
The challenge is to do all this while respecting customers' data privacy and remaining non-intrusive, Mr Raina notes.
"The question for each organisation at this juncture is what they do and don't do. We do a lot of testing to ensure our customers are comfortable with what we do. We have real customers come in to provide feedback.
"We have to provide help and products at the point that customers need without being intrusive. If we were to cross that line, it would become very uncomfortable."
But this is indeed the way of the future, he says.
"The companies that are first to create such an ecosystem will be the most powerful platform as they will be able to help customers across their whole life journey."