Challenger bank Tandem migrates to AWS in one weekend

UK digital challenger bank Tandem migrated from its initial IT infrastructure to the Amazon Web Services (AWS) cloud over just one weekend in November without a hitch.

The bank’s move from its IT infrastructure – hosted by a managed service provider approved by the banking regulator – to AWS was critical to cope with demand for computing power at a time of rapid customer growth, particularly as the company aims to acquire millions of customers and become a mainstream lender.

Tandem, which offers customers a credit card account and savings products as well as an account aggregation app, is striving to use artificial intelligence to offer customers information and support in managing their finances. It also plans to launch a current account.

The company obtained its banking licence at the beginning of last year when it acquired Harrods Bank. It gained about 7,000 customers of mortgages and savings accounts through the takeover, increasing its customer base to 21,000. But by November, following advertising and customer referrals, it had about 350,000 customers, and today has 500,000.

It was in November that the bank moved all of these customer accounts from its existing servers to AWS. With the huge IT migration disaster at TSB still making headlines, Tandem completed the task quietly and without a hitch.

“Last year we had some stuff on tin, but in November we moved everything onto AWS over a weekend,” said Tandem CEO and founder Ricky Knox.

It is now about 99% AWS, although it does have some data- related services on premise to support machine learning and AI tools. It uses AWS services throughout, including S3.

Knox said services such as AWS have allowed companies to scale rapidly. “In the past, we would sometimes run out of storage capacity or processors and it would often take weeks to order,” he said. “Now it is just auto-scaling.

“Today the worst thing that happens is if I get an unexpectedly high bill. This means you spend more than you expect one month, but that is a better problem, because if you are on physical infrastructure, it would actually break.”

Knox said Tandem worked closely with a team of eight people from AWS which the supplier offered to help with the migration. “There was no data lost and no customer complaints,” he added.

This is not the first time Tandem has performed an overnight customer migration. In March 2018, it migrated all 7,000 Harrods Bank customers onto its infrastructure in one night.