When John Mountain was hired by Starling Bank in 2015 as a solution architect, the company was a team of nine with no IT landscape, funding or banking licence. Within a year, Starling had raised £48 million, earned a banking licence and Mountain was CIO.
By 2017, Starling had the first mobile-only current account in the UK and moved to its new square mile headquarters where Mountain now stands, surrounded by the banking giants that the digital upstart has come to challenge.
"We're delivering at an amazing pace and with a small number of people, products which are better than teams of thousands are able to produce around the corner," says Mountain.
"And that requires a way of working, and an efficiency that I think is the impressive part about what the challengers are doing. The incumbents think that they will beat us with cash."
Starling has already replaced one of those incumbents as tenants. Swiss banking group UBS previously occupied this third-floor office space, and their trading floor clocks still hang from the ceiling, the digits frozen in time. Their light has now been eclipsed by the glowing flat screens beside them, whose displays show graphs that chart Starling's performance.
There's still a connection with financial traditions on the office floor, where a dapper ex-city banker reaches into a box of doughnuts.
"There are a lot of people who have worked in another retail bank, and are frustrated and want to have a serious crack at doing it better," says Mountain, whose own past led him to share their belief that banking could be better.
The graduate programmer had previously worked as a contractor for banks including Lloyds and Bank of America, and felt that they were failing to unleash the power of technology.
One of the ways in which Starling improves upon their use of tech is by building cross-functional teams, which explains why the Krispy Kremes fan sits opposite a millennial clad in a t-shirt and trainers.
"We all feel more comfortable if the three people at the desks around us do kind of a similar thing to us, but actually, it's more productive if, say, the group of people who are going to launch the business current account all have different skill sets and work together," Mountain explains.
This approach helps avoid the mistakes that arise when different teams work in isolation on separate components of a project.
"So what we do is, we group together a load of people around a vision of that service, and they're responsible for it, end-to-end. We've got the screens monitoring the system. You might have a designer and a programmer looking at the payment volumes and the feature they've just launched, and wondering what to do next, and they can have a conversation and make the necessary changes."
Starling moved to its new digs in September 2017 when the bank outgrew its old office. The current space is spread across 14,500 square feet that can fit up to 200 people, and CEO Anne Boden has plans to expand into Europe.
It was Boden's blogging that had first attracted Mountain to Starling.
"In that material was this very powerful statement that if you're going to run a modern bank, you need to do it without an IT department," he recalls.
"The departmental model is a big cause of problems. I read that and thought that sounds like a place where I want to work. We can do the tech and do the banking integrated."
Boden had learnt the trade over a 33-year career at some of the incumbents that her challenger now faces across the streets, culminating in an 18-month stint as Chief Operating Officer at Allied Irish Bank.
AIB's UK head office may only be a 10-minute walk away, but the businesses are miles apart. Boden describes Starling as "a licensed bank that won't really act like a bank at all".
She built the bank from scratch on digital and mobile foundations, while the incumbents have had to bake them in and try to catch up.
As the company grew from an idea through prototypes to launch, Mountain backed her product strategy up with systems delivery, vendor integrations and onboarding.
Customers can now manage their finances themselves, through data-driven insights that help them make better financial decisions. They receive push notifications of transactions, which can be divided into different categories and transferred to different digital piggy banks until they reach a saving target.
"We've put together a very good retail bank with a strong product," says Mountain. "But more importantly, some of the main things that we're pursuing, particularly around the open banking marketplace agenda are things some banks have neglected.
"Some banks are hoping we'd go away, but we think this is actually the future. This is what the customers need. This is what they deserve - the ability to take their banking data and do something else with it. Give it to someone else. Consume a third-party service using that data, or just consume other services more easily.
"You've onboarded your identity to us; it's a strong trust relationship. We've done a variety of KYC [know your customer] and background checks at onboarding. We're in quite a strong position to get you into the next service you want to consume without a fight."
Collaborating with consumers and authorities
Retail banks must understand consumer desires and create the services they want. This is even more vital for challenger banks, which have to build their customer bases through word-of-mouth.
Starling does so by testing new ideas with the Starling Bank Community, a forum in which the bank shares plans and receives feedback from users.
"They have some pretty exotic ideas, and sometimes we get inspiration there," says Mountain. "We do customer research, where we assemble panels and ask them questions. We will come up with our own ideas. We've got lots of people with quite deep experience in the industry, in retail banking, in other banking sectors, and we will just hypothesise ideas and then try and test them.
"I think one of the principles of modern software delivery is that you probably don't know the answer, and rather than trying to know the perfect answer up front and then go and deliver it, I see a big part of my role as making sure we can build and deliver really fast.
"Then you can experiment. It's not going to kill us to build a feature and put it in front of people and then realise it's wrong. And strategically, if the tech delivery can be fast, then we can operate like that, and we have more chance of success."
The financial authorities have proven to be supportive of their experiments. The regulators changed bank licensing rules to encourage challengers to shake up the existing order in 2014, the same year in which was Starling was founded.
Regulation and security
Starling collaborated with the regulators from the bank's inception, demoing the product and addressing any concerns that they raised.
"The process of licence application to mobilisation was over a year, and over that period we were working with them very closely on analysing and auditing the product and service, and getting to the point of knowing this service is fit and proper to provide a UK retail bank account," says Mountain.
Security will always be a priority for banks. Starling ensures it through a combination of multi-factor authentication, internal monitoring and sending customers notifications of unusual activity.
"One of the best things you can do for cyber-security is keep the customer as the best person to monitor their own account. Obviously, we do our own monitoring as well, and we have systems looking at this and scanning for any fraudulent or suspicious activity, but keeping the customer absolutely informed of everything going on in their account is also incredibly powerful.
"The classic thought pattern if someone were to steal your card, is that they'd tend to go and try a couple of low-value transactions to see it is still live, and then, once they think they've got a live card, they'll go to something bigger. Well, if you see that 15 pence go through, and say, 'What was that?' you can kill it. Those ideas are pretty central, and we're seeing some of that crystallised into the PSD2 technical specifications."
Winning hearts and minds
In the ground floor café, Mountain buys a pot of tea with his Starling app.
UBS HQ is still within spitting distance of where we sit, ensconced in a 12-floor steel fortress. If Starling is to emerge from such towering shadows, it will do so by providing a distinctive service that arises from a startup mentality.
"One of the ideas behind being a digital challenger is not just to produce loads of great tech in support of the customers but that tech businesses don't need to be 20,000 people," says Mountain.
"We're not a huge company. There's 145 people working at Starling, and we're growing, but the part of the organisation that does product and technology and customer research is not going to grow crazily.
"Customer services will grow, in line with the business, and to some extent, operations will need to grow as they process more volume, but the other parts of the organisation are probably not going to grow super-fast. We grow carefully. We hire very carefully. Our ability to do this with a small number of people is going to be increasingly important as the market evolves."
Mountain admits that the incumbents have upped their game under pressure from the challengers, but adds that they will always be catching up with the more agile tech firms.
Starling also faces competition from the growing selection of digital banks, but Mountain views them more as fellow challengers taking on the same establishment.
"We have a friendly rivalry with the other challengers, but the job in front of us is to convince people in the UK that a digital-only service is not only useful, but it can be the only account they have," he says.
"That's the challenge. The competition is not a specific incumbent bank; it is that wider mindset of what a bank looks like: a shop on a high street with a colourful logo. We need to change that."