The move to multi-cloud environments accelerated at the onset of the COVID-19 pandemic in early 2020 as organisations around the world mobilised new, hybrid work environments.\nCompanies are using multiple cloud service providers to support their remote workforces while retaining an increasingly smaller portion of their on-premise estate. The absolute majority (90 percent) of enterprises are now operating in hybrid and multi-cloud environments, and 25 percent of all IT workloads are now in the cloud.\nSenior technologies executives gathered for a conversation recently around how they are making multi-cloud environments work for their organisations. The discussion was hosted by CIO Australia and sponsored by Google Cloud and Accenture.\nA key question was how CIOs decide which cloud service is right for which workloads so they can create efficiencies, cut costs and drive business value.\nRob James, Group Chief Digital and Information Officer at TPG Telecom, says that when looking for the right cloud, the telco assesses the requirement from a capability perspective. That often means that a SaaS [software-as-a-service] offering may be best placed to deliver on a business capability, he says.\n\u201cIf the capability goes down to a bespoke development or application that IT needs to host for the business, then we will select an IaaS (infrastructure-as-a-service) or PaaS (platform as a service) offering. This will typically be strategic and driven by many levers such as cost, availability and functionality.\n\u201cThis important aspect here is that we have an environment that we are able to control and manage but in a true cloud format that is using as much digitisation and automation that makes sense,\u201d he says.\nPeter Brusco, Chief Information Officer at Kangan Institute, says the government-funded tertiary institution is very fortunate to access large-scale government cloud agreements that can be deployed quickly, saving time and money.\n\u201cThey also provide high levels of certainty from commercial, technical and security standpoints,\u201d he says.\n\u201cHowever, there are still choices to be made and so it\u2019s very important to understand near and far-term requirements as much as possible to select the best outcomes. We don\u2019t have a crystal ball to understand, with precision, our future needs, I like to engage in some basic scenario based on our best forecasts and then do a \u2018what if\u2019 [analysis] based only a quarter, or alternatively, four times our projections.\u201d\nAndrew Haschka, Asia-Pacific Head of Application Modernisation at Google Cloud, advises CIOs to ensure their cloud services are portable and flexible enough for long-term, dynamic growth.\nBy elevating applications beyond specific cloud, empowered by open-source software, CIOs can reduce vendor lock-in, he says.\n"Production support and enterprise security should also be priorities when considering the future of applications, and implementing a common security standard across platforms for security. Google provides Anthos for example to manage modern application portfolios for multi and hybrid cloud environments, based on Open Source technologies such as Kubernetes.\nCultural transformation in managing a microservices architecture requires benchmarking and SRE skill uplift too. Google have pioneered DevOps cultural benchmarking and transformation with the Cloud Application Modernization Platform (CAMP) driven by DevOps Research & Assessment (DORA)\u201d\nAl Auda, managing director, Accenture Technology, Cloud Infrastructure Engineering, Australia and New Zealand, suggests CIOs think about their \u2018cloud north star\u2019 first and the different treatment types for applications before mapping those to specific workloads.\n\u201cWe are seeing companies move their commodity enterprise applications \u2013 such as HR and payroll \u2013 to SaaS, rehosting\/re-platforming existing legacy core systems to IaaS and building new digital platforms on PaaS.\n\u201cIn highly regulated industries, designing applications that can support multi-cloud providers is becoming a need with a shift to lightweight containerised cloud-agnostic applications. Many clients are splitting their workloads across multiple clouds for healthy competitive tension and to use the strengths of specific cloud providers for their industry and application portfolio,\u201d he says.\nThe modernisation challenge\nA big challenge for many organisations moving to multi-cloud environments is deciding what to do with legacy systems and applications. Should they be modernised, left alone or replaced?\nTPG\u2019s recent merger with Vodafone created a lot of legacy and duplication, which is expected, says TPG\u2019s James.\n\u201cThe legacy platforms provide an extra level of complexity as they are never architected for the cloud and there is very little to no benefit of \u2018lifting and shifting\u2019 so the typical conversation becomes whether we modernise, retire, refactor or repurchase the application. After a merger, like the one we experienced, there may be a need to consolidate where you have a number of legacy applications doing the same thing.\u201d\nEffectively modernising applications across a multi-cloud infrastructure is becoming a very real issue, potentially eroding some of the simplification which CIOs are always looking for, says Kangan Institute\u2019s Brusco.\nHe says that while \u2018single pane of glass\u2019 solutions have been spoken about for some time, the completeness of solutions available as well as their cost are still not sufficiently attractive for many organisations.\n\u201cThe other key issue is that internal technology teams are not transforming the skills and approaches required to match the migration from data centre to the cloud. When large-scale technology transformation takes place as it is occurring at Bendigo Kangan Institute, the way of thinking in this new multi-cloud environment requires significant change on the part of both users and the internal technology team,\u201d he says.\nMeanwhile, Stuart Bromiley, Accenture Google Cloud Practice Lead, Australia & New Zealand adds that one of the main challenges the company\u2019s customers are dealing with when it comes to modernisation is how to treat their old legacy systems. Many of these are running on decades-old platforms and operating systems that are no longer supported and have a \u2018high bar\u2019 security compliance and to put these apps in the cloud requires significant security and upgrade\/re-platform remediation, he says.\n\u201cIf a data centre exit is imminent and an app needs to move to the cloud, then we would recommend a \u2018move and improve\u2019 approach. As part of the move, organisations should have a pattern to minimise re-platforming for old apps that will be retired soon through emulation\/virtualisation techniques,\u201d he says.\nBromiley says Accenture has worked with many clients on using a \u2018digital decoupling\u2019 approach when modernising a legacy app. He advises that organisations start by decoupling read-only data with change data capture to build a digital experience on top, and application programming interfaces (APIs) on top of the legacy platform before gradually replacing the functionality of the legacy monolith with a new digital application.\nOne or many cloud providers?\nSome organisations have moved the absolute majority of their IT systems and applications to one cloud provider, while others prefer to put their eggs in more than one basket.\nLike many other organisations, TPG runs a multi-cloud environment with its primary cloud provider being AWS. Google is providing some more unique services and the company\u2019s Office 365 and Active Directory services hosted by Microsoft Azure.\n\u201cWe see that there may be some benefit in being able to move applications that have been architecture for portability to different cloud providers \u2013 for example, when utilising containerisation \u2013 but there is very little commercial benefit in trying to do that as a strategic imperative,\u201d says TPG\u2019s James.\n\u201cThe other challenges when trying to move workloads around is that you dilute your spend with any one cloud provider, which then encroaches into any discounts or investments that you can negotiate from a single provider.\u201d\nA single cloud environment can be easier to manage for smaller and simpler environments that may not have the technical resources required internally, says Kangan Institute\u2019s Brusco.\n\u201cIt is simpler to move workloads to and from a single cloud and it can still provide good cost benefits,\u201d he says.\n\u201cThe downside is that while it\u2019s simpler to manage a single cloud provider, it can be more difficult when things turn sour with the cloud provider. Most organisations migrating a workload to the cloud usually find themselves moving into multi-cloud environments.\n\u201cThis is driven by the different offerings and costs of the various cloud providers. It is also driven by organisations wanting the risk diversity that comes with multi-cloud environments even if there is a higher management overhead,\u201d he says.