An IT Leader’s Guide to App Modernisation Routes
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An IT Leader’s Guide to App Modernisation Routes   

All responsible digital transformation leaders are talking about it, but what does app modernisation actually mean?

Application modernisation – the process of updating or replacing core business apps or their deployment platforms – is designed to make infrastructure perform with greater efficiency and flexibility.  

The objective? To enable app performance and capabilities that align more strongly with organisational needs. Increasing agility, resiliency, innovation and overall competitiveness are commonly cited areas where app modernisation can deliver transformative outcomes.  

On top of that, app modernisation is considered a strategic pathway for reducing operational risk, security vulnerability and direct or indirect expenditure, which can, of course, have significant impact on wider business performance.  

With that in mind, addressing app modernisation should be high on the technology leader’s agenda in order to remain effective, competitive and attractive to a future (and far more discerning) customer. Not doing so can be a barrier to achieving a desired security, digital transformation and growth position, but app modernisation itself has historically been hampered by its own accessibility barriers.

What are the challenges of application modernisation in 2022?  

App modernisation is a key juncture in many cloud migration roadmaps – after all, effective digital transformation happens over time and continually evolves. 

Those wishing to modernise their core business applications or computing services have several established routes to pursue, but no single approach is a silver bullet. The challenges of app modernisation lie largely in evaluating where a benefit will be so worthwhile that a transformation effort is demonstrably worthwhile.  

It’s necessary, then, that project leaders establish a balance between achieving business objectives versus time, cost, risk and oftentimes, long term sustainability. A recommended strategy will be unique to a business, but a typical approach is to start with apps that have high value and lower resource demands to modernise. Essentially, that means identifying quick wins to kickstart transformation from which momentum can be gained.


After establishing an acceptable baseline of expenditure, delivery time and risk, organisations by and large embark on one of these three routes of app modernisation.  

Rehost or Replatform

Colloquially referred to as “lift and shift”, in the context of app modernisation rehosting or replatforming means to migrate existing apps to your desired cloud environment without making any changes to the app itself. Azure, for example, is becoming an increasingly popular platform for the lift and shift approach but it isn’t appropriate in every case. 

Although lift and shift theoretically solves some of the problems associated with running outdated apps – and does so quickly and cost-effectively – this route may prove more problematic in the long run. This is for two key reasons: 

Firstly, any limitations posed by in-app functionality will persist within your new deployment environment, meaning eventually, more extensive app modernisation work will need to be undertaken. As such, lift and shift is sometimes considered a temporary measure to increase the performance of on-premises or legacy apps while a roadmap is progressed in stages. 

Buying time in this manner is not without its benefits. But it’s important to note that integrating on-premises applications and cloud environments calls for a clear understanding of the characteristics to support on each side alongside hybrid architecture that designs in the functionality, security and performance, which will in turn offset the risks of re-hosting or re-platforming. As you’d imagine, extensive analysis of your app pre-cloud migration and a potential roll-back plan are vital prerequisites.  


A step up from lift and shift, both refactoring and rearchitecting involve making changes to an application’s code as a means of modernisation.  

Refactoring is commonly used as part of a cloud migration strategy. It sees minimal code and configuration changes made to an application to function optimally in a cloud environment such as Azure Platform as a Service (PaaS), thus leveraging its agility, scalability and cost benefits. 

Rearchitecting encompasses more extensive changes to on-premises application code and may be necessary for many legacy or particularly fragile on-premises apps. Developers will change the app’s code base to both optimise it for cloud deployment, and ensure it’s capable of scaling within cloud platforms, often with Azure or other cloud providers in mind.  

Both routes come with more significant cost, expertise and time demands than lift and shift, with stronger guarantees of enhanced performance and lifespan for apps designed and used on-premises. However, rearchitecting – albeit higher risk – can deliver better results. 


The third of our three well-established application modernisation routes is rip and replace. Referred to by some as the “all or nothing” approach, rip and replace (or rebuild and replace) essentially means to start again. Daunting, but occasionally necessary. 

Where an application is proprietary, rip and replace may mean investing in a total rebuild of using appropriate cloud native environments such as PaaS, IaaS or SaaS, with updated functionality front of mind. Where an app is licensed or purchased, organisations may walk away from their on-premises solution and invest in its cloud alternative. Or they may switch to an app that better suits business objectives and other key determinants.  

As a major change to a core business application, the pitfalls of rip and replace can be severe if not analysed, planned for and the migration rolled out appropriately. From teething problems to unsuitable features or performance, this expensive route to app modernisation needs not only to mitigate any post-migration productivity dip but generate a return on investment quickly.  


Microsoft Azure Stack HCI is an excellent route to app modernisation in a wide range of scenarios. It offers flexibility and risk mitigation that replatforming, rearchitecting and rip and replace struggle to replicate, while delivering the performance benefits of all three while a strategic digital transformation roadmap is funded and progressed. 

Azure Stack HCI has rapidly evolved from an emerging app modernisation solution to the most viable option for many IT leaders wanting guaranteed, low risk, cost-effective results.  

It enables organisations, MSPs and ISVs to modernise on-premises applications within Azure – providing a gateway to the cloud while on-premises remains in use. 

With Azure Stack HCI, apps can be redeveloped and built from scratch as required within Azure PaaS. Apps can be modernised while still running on the platforms they were designed for, reducing risk of disruption or hastened time to market or roll-out. Developers may also use Azure Stack to get their app ready for public cloud migration. 


Azure Stack HCI describes itself as a “flexible hyperconverged infrastructure delivered as an Azure hybrid service”. With this delivery model, you’d be right to assume that the app modernisation solution is suitable for a wide range of workloads and businesses.  


  • Wide range of app capability within VM or container context, including Windows and Linux apps  
  • High-performance SQL Server databases and big data clusters  
  • Virtual Desktops Infrastructure (VDI) with edge-local access  
  • Container based workloads such as Azure Kubernetes Service (AKS) 
  • On-premises resiliency for Azure-hosted PaaS services e.g. App Service and Azure SQL 


  • Independent Software Vendors (ISVs) developing your apps for the wider market and MSPs 
  • Managed Service Providers (MSPs) developing your apps for solutions/services delivery or internal functionality  
  • Larger or leading-edge organisations developing proprietary apps  


A selection of benefits that Microsoft and its Azure Stack HCI customers enjoy include: 

  • Low latency from a high-performance platform in a local location  
  • Control and visibility over data sovereignty  
  • Option to run workloads from a location that delivers optimum performance  
  • Integrations with Azure’s wider service portfolio  
  • Ease of use, with the same toolset for on-premises and Azure public cloud 
  • Repeatable solutions with capability extended to on-premises development  
  • Additional configuration, availability and security support when deployed with an Azure Expert MSP, such as Node4  


Many organisations – whether modernising apps for the market, service delivery or internal operations – can dispense with the risk associated with lift and shift and achieve the wide-reaching benefits of more costly rearchitecting or rip and replacing. 

Developers can build or redevelop apps once, which can be simultaneously deployed on-premises or in public clouds like Azure. This helps migration in three main ways:

  1. As a hybrid cloud route, Azure Stack HCI enables a public cloud transition at your own pace. Of course, many organisations such as those where low latency is fundamental to continuity and safety (healthcare, manufacturing, pharmaceutical for example) will always require data processing close to the source, either as edge devices or on-premises servers. Azure Stack HCI gives you this flexibility while enabling apps to be deployed across all hybrid infrastructure and simultaneous access to a wider portfolio of Azure services. 
  1. The hybrid solution to modernisation also wins back important time which can be spent developing the best possible app for market, spreading the cost of transformation and reducing the operational risks of a direct on-premises to public cloud migration. 
  1. Additionally, your development team can solely focus on modernisation, safe in the knowledge that on-premises, business-critical apps continue to run on their optimal platform without the risk of downtime. This focus could promote a competitive edge that gets your app modernisation project across the line on time, on budget.


As one of a select few Azure Expert MSPs, Node4 can help your organisation combine the latest in hybrid technologies with our Managed Azure Hybrid Cloud service. Run workloads in Azure and data centres with a single, integrated set of tools including Azure Stack HCI for app redevelopment. Learn more and enquire today