The Australia and New Zealand Banking Group (ANZ) has built its main banking website using Amazon Web Services (AWS); likewise, the work it undertakes with its fintech partners is performed using the AWS cloud.
But when the bank partners with most of the universities in Australia, it jumps onto IBM's Bluemix, and still uses internally-hosted servers when running things like hackathons.
According to Christian Venter, GM of Consumer Digital Technology at ANZ Bank, the bank is also starting to evaluate other cloud service providers like Azure and Google.
"Because they've all got different service levels, different services for different things," he explained.
"Like everything at ANZ, we use everything.
"But we do make conscious decisions about where we deploy and why we deploy."
Speaking at CeBIT Australia in Sydney on Tuesday, Venter said the bank has moved into the cloud for a few different parts of its organisation and has realised a handful of benefits as a result.
"We can get in far quicker than we ever have before, our cost to innovate and barrier to entry to innovate is very low," he explained.
"We get better time to market for our features as a result of that and it's lower cost.
"We buy infrastructure today and we size a box to its maximum capacity, then we pay the depreciation on that for the next four years, the reality is, we don't use that capacity, so that capacity is sitting there wasted -- with cloud, we pay for what we use.
"Effectively you pay for use and that's an extraordinary difference when you see that."
Where privacy and security is paramount, ANZ is sticking to its private cloud; however, it is starting to expose its integration APIs to the public cloud as well.
Commodity services like anz.com and the bank's remuneration and rewards system are sitting as software-as-a-service on the public cloud; similarly its mobile apps that deal with financial transaction and market data are hosted on AWS.
"Sometimes we innovate using public data; other times if it's something sensitive ... we'll do it internal on our own cloud," he explained.
Some of the benefits Venter said the bank has reaped as a result of its multi-faceted cloud strategy include the consolidation of 30 physical datacentres down to three; its hardware costs are down 25 percent; its footprint on the environment is down significantly; its server runtime is down from months to minutes; and the bank's test and learn time has also reduced from months to weeks.
"Because of putting these things in place, it's been great," he said.
"We're also starting to move a lot of our internal delivery capability onto cloud technologies
"The one thing we have learnt is the technology stack that you lay on top of that is important. You can get the infrastructure now very quickly; however, what you do with it is still your competitive advantage to a degree."
In addition to all of the cloud vendors it employs, ANZ uses applications from the likes of Docker and Red Hat, as well as employing the Atlassian suite from "end-to-end".
The bank has also recently adopted Sky High, another application that allows ANZ to monitor all of its cloud deployments.
As one of Australia's largest banks, ANZ has to answer to a strict governance framework, which Venter said needs to be front of mind every time the bank puts something in the cloud.
ANZ announced earlier this month it would be adopting the methods used by tech giants Google and Spotify in a bid to quickly respond to changing customer expectations, engage and empower staff, and improve efficiency within the bank.
The Scaled Agile approach to organising and delivering work has been touted by ANZ as a proven approach for running businesses based on small, autonomous, multi-disciplinary teams.
According to the bank, it already uses agile to deliver around 20 percent of its tech-related projects including initiatives such as Apple Pay, which ANZ launched in April last year.
The announcement was made the same day ANZ released its results for the first half of the 2017 financial year, which saw the bank post a 6 percent year-on-year increase in after-tax profit to AU$2.9 billion for the six months to March 2017.
"These results show we are creating a very different bank, one that is consistently producing better outcomes for customers and for shareholders. These are still early days and I am pleased with the significant momentum we have now established in the business," ANZ CEO Shayne Elliott said at the time.
As the bank focuses on competing in the digital age, ANZ general manager of data Darren Abbruzzese revealed in February ANZ was embarking on a project to create an enterprise-wide data lake in a bid to capitalise on the most strategic asset the bank believes it has.
According to Abbruzzese, as the bank realised the value of its data, it captured everything it could. However, as a result, little "ponds" of data popped up in different departments throughout the organisation, and the information inside remained valuable and accessible only to those working on a particular project.
As a result, ANZ is aggregating its data into a single Hadoop-based data lake, which will also see the bank move away from the concept of data warehouses.
Abbruzzese expects the process to take a number of years.