Starling Bank will "definitely" be profitable by the end of 2019 according to its CEO, the payback for an innovative product born in the Amazon cloud.

The digital-only bank built its platform in-house from the ground up on Amazon Web Services (AWS). Anne Boden, Starling's founder and the former chief operating officer of Allied Irish Bank, says the move to AWS would have slashed a huge chunk out of the IT bills she ran up in her previous role.

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Image: Starling Bank

"What had taken me £30 million people were doing [in the cloud] for £30k", she told IDG Connect.

Starling uses AWS to deliver and scale a secure infrastructure automatically and on demand. The challenger bank primarily uses Amazon CloudFormation to provision and manage its AWS services, and Amazon EC2 to run its applications on virtual machines in the Amazon cloud.

It also uses S3 to assist with data storage, Amazon RDS to run its relational database in the cloud, and AWS Lambda to help build a responsive and on-demand application.

"It's been a large part of what's enabled us to essentially build a bank in a year," Starling's chief technology officer Greg Hawkins tells Techworld.

"Over the course of 2016, we built the production infrastructure which is the bank today and then went to the app stores a few months later, in spring this year," he explains. "To this day we are based entirely in the cloud. It's an essential part of what's enabled us to deliver as quickly as we have and as reliably as we have over the past year and a half."

How Starling uses AWS

Hawkins says that the primary advantage of AWS is the low cost of innovation. Instead of devising strategies and running up bills on ideas that may not work, the bank can rent additional compute power and memory on Amazon's virtual computers to experiment with new ideas and change their plans based on the results.

"You don't have to commit to things," explains Hawkins. "You can afford to make mistakes and learn from those mistakes, and wipe the plate clean and carry on going."

The ability to quickly roll out new updates has been another major benefit.

"No sooner can you think what you want then you write some software to have it in production."

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Starling has also used the service for more sophisticated purposes. For example, the bank has automated engineer access to new releases through a Slack bot integrated with Amazon Identity and Access Management (IAM). The user types in their request for enhanced production privileges, and if they're eligible through the IAM record it will be granted.

Starling can also take advantage of Amazon's massive investment in emerging technologies, which it rolls out to its customers at a bargain rate compared to the cost of developing them in-house.

"Some of the things that the cloud does is democratising some of these high-end capabilities and made them available to you without having to make big investments," says Hawkins. "We move very fast by taking advantage of those capabilities."

Why AWS?

Hawkins says that AWS was the obvious choice of cloud provider, but adds that Starling will still consider moving some of its workflows into its cloud competitors.

"Their infrastructure is basically the same size as all the others put together and the maturity of the platform and the structure of the platform make all the others look pretty young and immature," he explains.

"Mobility between different cloud providers is part of the long-term plan, but we have no regrets about going with AWS first and we recommend that really to any startups. In terms of the breadth and depth of the offering that's available, there's really nothing to hold you back with AWS."

Read next: 'Banking is broken and we must start from scratch', says Starling CEO Anne Boden

Although Hawkins still sees services from other cloud providers in Starling's future, he's far less likely to turn back to an on-premises IT environment.

"Part of the thing about using the cloud is that there's no restriction in achieving what it is that we want to do, and the idea of going back to on-premises or physical infrastructure is pretty odious to me."