Real-world use cases and examples of application modernization

• What are common application modernization use cases?
• What is an application modernization example?
• How do companies migrate from on-prem to cloud?
• What do successful modernization outcomes look like?
• How does app modernization improve customer, patient, and employee experience?
• What lessons can be learned from failed app modernization projects?

Application modernization is a set of choices companies make when existing applications cannot support business goals at an acceptable cost or level of risk. These choices show up as use cases in a trustworthy, incremental plan that connects each use case and its related activity to one or more measurable outcomes.  

That plan should demark use cases that identify applications to retire, retain, relocate, rehost, replatform, repurchase, or refactor because treating every application the same usually increases cost and risk.

Common app modernization use cases include:

• Reducing the cost and effort required to maintain aging applications
• Moving away from unsupported software, hardware, or programming languages
• Improving application security and regulatory compliance
• Increasing system availability and recovery speed
• Releasing new products and features more frequently
• Connecting applications and data that were built in separate silos
• Preparing core systems to support automation, analytics, or AI
• Improving slow, complex, or inconsistent user experiences
• Scaling applications to handle growth, seasonal demand, or new markets
• Replacing manual processes with digital workflows
• Reducing dependence on scarce technology skills
• Moving selected workloads to cloud, private cloud, software-as-a-service (SaaS), or a hybrid environment
• Prepping the enterprise for AI transformation at scale

The right use case starts with a business driver, not a preferred technology. Here are some real-world examples from Slalom’s portfolio of engagements.

North American retailer, DSW, wanted to build a flexible, scalable loyalty platform so the brand could offer customers more personalized shopping experiences, faster, and drive more revenue and loyalty. Read the story

The Academy of Motion Picture Arts and Sciences wanted modernize their operations, streamlining processes from awards submissions to rolling out the red carpet. By replacing many of their architectures and apps with a single, integrated system, the Academy could move more quickly and with far less friction, not just by achieving their initial goals, but opening up capacity to pursue talent development initiatives that were once parked in the margins. Read the story

LG CNS, the consulting and services arm of the LG (the technology giant), needed to operate with more speed and adaptability, and evolve the entire way they operated, especially in their product development life cycle. With their commitment to modernization, including application modernization, LG CNS retooled their 5,000-person engineering organization into one that can easily deliver the cloud-based migration, ongoing modernization waves, and new product development. Read the story

A strong example of application modernization in financial services is PayChoice, an Australian payments provider that modernized its legacy, on-premises payment platform by migrating to Amazon Web Services (AWS) to support growth, improve resilience, and strengthen security.  Read the full PayChoice story

As PayChoice expanded beyond Australia, its aging infrastructure made it difficult to onboard new customers, meet enterprise expectations for cloud-based services, maintain the Payment Card Industry Data Security Standard (PCI DSS) compliance, and scale without adding costly hardware or operational overhead. While a lift and shift to the cloud was one early option, the company modernized its architecture by implementing cloud-native networking, security, database, and infrastructure services.

The results extended well beyond infrastructure improvements:

• Faster scalability: PayChoice can now provision infrastructure on demand and onboard customers much more quickly, supporting expansion into New Zealand with plans for the UK and Middle East.
• Improved operational efficiency: Automated patching, backups, monitoring, and infrastructure management reduced manual operations, allowing technical teams to focus on innovation instead of maintenance.
• Greater resilience: A cloud-based architecture eliminated scheduled monthly maintenance windows and introduced high availability with virtualized disaster recovery.
• Stronger security and compliance: Native AWS security services—including Web Application Firewall (WAF), AWS Control Tower, AWS Network Firewall, and built-in security controls—simplified PCI DSS compliance while improving protection against cyber threats.
• Better performance: Data retrieval tasks that previously required four to five hours now take about five minutes.  

This example illustrates a broader trend across financial services, but the principles apply to every industry. Application modernization is no longer just about migrating workloads to the cloud. It's about replacing rigid legacy environments with secure, scalable, cloud-native platforms that improve customer experiences, accelerate product delivery, reduce operational costs, and create the foundation for AI, analytics, and future innovation.

Companies don’t usually move every application to the cloud, at least not all at once. First, leaders must pinpoint the business purpose for the move and then choose the right priorities and treatment for each workload. This shows up in a portfolio assessment.

A portfolio assessment typically considers:

• Business criticality
• Technical condition
• Application and data dependencies
• Security and compliance requirements
• Performance and latency needs
• Current and future operating costs
• Software licensing
• Recovery requirements
• Internal skills
• Expected lifespan of the application

Leaders can then choose among the 7Rs for multiple migration strategies (retire, retain, relocate, rehost, replatform, repurchase, or refactor), and execution should take place in controlled waves. But, leaders must establish cloud governance, identity, networking, security, observability, backup, financial controls, and deployment automation before moving critical applications. Only then is it appropriate to migrate a limited set of workloads, validate the operating model, and expand based on evidence.

For important systems, teams may run old and new environments in parallel, test recovery procedures, rehearse cutover, and maintain a rollback plan.  

Migration is not complete when an application starts running in cloud. It is complete when the organization can secure, support, recover, optimize, and improve the application consistently.

Successful modernization produces measurable improvements in the business and in the technology operating environment. A new architecture is not an outcome by itself. 

Leaders should define success across several areas including business, customer or patient, employee, engineering, AI, financial, and security and resilience outcomes.

• Faster launch of products, services, or responses to market changes
• Lower cost to operate or change important business capabilities
• Increased revenue, conversion, retention, or service capacity
• Reduced exposure to unsupported technology
• Lower financial impact from downtime or security incidents

• Faster page, application, and transaction response
• Fewer failed or abandoned digital interactions
• More reliable access to services
• Greater consistency across channels 
• Reduced need to call or visit for routine requests
• Better accessibility and personalization

• Fewer manual steps and duplicate entries
• Less time spent switching between systems 
• Reduced support tickets and workarounds
• Better tools for frontline decisions
• Faster access to more, and more accurate information for more informed decision-making

• Shorter lead time for changes
• More frequent and safer releases
• Lower change-failure rates
• Faster recovery when incidents occur 
• Higher automated-test coverage
• Clearer ownership of applications and services

• Lower infrastructure, licensing, or support costs
• Reduced cost per transaction or user
• Less spending on avoidable maintenance
• Greater engineering capacity for strategic work
• A clearer and more predictable cost model

• Stronger identity and access controls
• Faster vulnerability remediation
• Improved audit evidence
• Tested recovery procedures
• Reduced outage blast radius
• Better visibility into application health and dependencies

The organization should establish a baseline before work begins and track a small set of outcome measures after each release. Modernization succeeds when the business can see sustained improvement—not when the project completes a technical checklist.

Application modernization improves a human’s experience when it removes friction from an important journey. A new front-end interface won't reduce friction if it runs on slow or poor integrations, unreliable data, or manual work behind the scenes. The strongest experience gains come from modernizing the full workflow. That may require changes to applications, integrations, data, identity, business rules, and team responsibilities.

Leaders should measure experience using operational evidence such as:

• Time to complete a task
• Abandonment or error rate 
• First-contact resolution
• Call or support volume
• Cart abandonment
• Employee effort 
• Patient or customer wait time
• The number of manual handoffs and break points
• Digital adoption
• Accessibility performance 
• Satisfaction and trust

For customers, modernization can create faster digital interactions, consistent information across channels, simpler account access, more reliable checkout or service requests, and quicker introduction of new features. It’s also a meaningful path toward operational efficiency, cost savings, and pricing optimization.  Read about The Home Depot’s market intelligence acquisition and modernization journey

For patients, it can make appointments, records, messages, billing, and care instructions easier to access. It can also give clinicians and service teams more complete information, reducing the burden on patients to repeat their history. These changes must be designed around privacy, accessibility, safety, and clinical workflow—not just consumer-app conventions. Read about Renown Health’s digital transformation

For employees, modernization can reduce duplicate data entry, remove manual handoffs, and bring information from several systems into one workflow. That can help contact-center representatives resolve issues faster, help clinicians spend less time navigating systems, and help field or store employees serve people without leaving the interaction. Read about the City of Charlotte’s legacy transformation

Modernization projects usually fail because leaders misjudge scope, dependencies, organizational readiness, adoption, or operational risk. The most reliable modernization programs create value in stages. They make assumptions visible, test the hardest risks early, maintain senior accountability, and define conditions for continuing, changing, or stopping the work.  

10 lessons appear repeatedly.

Start with a business outcome, not an architecture trend. “Move to cloud” or “get AI ready” is not a complete objective. Teams need to know which business constraint they are removing and how progress will be measured.

Do not modernize the entire portfolio with the same approach. Some applications should be retired or replaced. Others need only targeted improvements. Deeply redesigning every workload wastes money and extends delivery timelines. Work with a consultant who can help you identify priorities, tradeoffs, and all the levers that can help you get where you need to go.

Map dependencies before changing critical systems. Applications often rely on undocumented interfaces, scheduled jobs, shared databases, manual processes, and specialist knowledge. Get this data from your manuals and inside of people’s heads. Missing these dependencies can lead to outages, data defects, and delays.

Avoid the large-scale rewrite trap. A multiyear rewrite can consume significant funding before users receive value. Incremental delivery allows the organization to validate assumptions, reduce risk, and change course.

Build the operating model with the technology. Modern platforms require automated delivery, observability, security engineering, cost management, service ownership, and production support. A new architecture without these capabilities is difficult to run safely.

Treat data migration as a major workstream. Poor data quality, unclear ownership, inconsistent definitions, and difficult cutover requirements can muck up the critical path. Data should not be treated as a final technical task.

Protect business continuity. Critical modernization needs tested fallback procedures, phased cutovers, production monitoring, recovery rehearsals, and clear decision rights during incidents.

Fund adoption and process change. Users may continue relying on spreadsheets, manual workarounds, or old interfaces if the new system does not fit the real workflow. Training alone is not enough; teams must redesign processes and reinforce new behaviors.

Measure total operating cost. A modernization project can reduce infrastructure cost while increasing spending on tools, data transfer, support, and specialized skills. Leaders need an end-to-end cost model, and they need to be tracking with an accountable partner(s) all along.

Preserve exit options. The organization should understand how it will move applications and data, replace a vendor, or change platforms if cost, performance, strategy, or regulation changes. Dependency should be a deliberate choice, not an accidental result.

The strongest application modernization programs do a small, but powerful handful of things well:

1. They prioritize the applications that matter most (resisting blanket solutions).
2. They match each workload to the right modernization path (avoiding wholesale rewrites).
3. They measure value after every release (to support architecture-led decisions and future funding tied directly to business outcomes).
4. Similarly, they avoid “the big bang” approach, and modernize iteratively.