Application Modernization: Ensuring the Stable Operation of Future-Proof Applications
We Bring Your Applications Safely to the Cloud
Application Modernization for Legacy Systems
Modernization that pays off in day-to-day operations - not just during the project
Modernize your applications with minimal disruption, transparent cloud costs thanks to FinOps, and a strategy tailored to your application. Arvato Systems develops API-driven IT landscapes with modular cloud services and combines analysis, implementation, and operations into an integrated model. This pays off where it counts: in day-to-day operations.
Incidentally, most modernization projects fail not because of the migration itself, but because operations, cost control, and resilience are only addressed afterward.
Start with a structured architecture and operations review—clear, risk-minimized, and actionable.
What Exactly Does “Application Modernization” Mean?
Application Modernization—also known as application modernization or legacy modernization—refers to the targeted further development of existing applications to make them cloud-ready, scalable, and sustainable in the long term—from a technical, organizational, and operational perspective. Arvato Systems not only supports the project but, upon request, also manages the operation of the modernized application.
Why Legacy Applications Become a Problem
74% of CIOs in Germany are driving IT modernization because legacy systems no longer adequately meet future requirements (Lünendonk, 2026). Almost every IT department is familiar with the reasons behind this:
Growing Pressure for Change
New business requirements or collaboration with other companies place new demands on existing applications in order to guarantee a smooth process.
Technical Debt
Outdated architectures increase development and operational costs. At the same time, making changes becomes more time-consuming, and it becomes more difficult to plan modernization projects.
Cloud Transformation
Cloud migration and data center transformation are changing the requirements for existing applications. Architecture, operations, and interfaces must be adapted accordingly.
Complex Integration
SAP, legacy, and cloud systems must work together reliably. Different architectures and interfaces increase the effort required for customization.
Organizational Change
Spin-offs, new structures, or a change in service providers alter the requirements for applications and their operation. Rigid structures make such changes more difficult.
Increasing Regulation
DORA, NIS2, and the GDPR are raising the bar for security, resilience, and auditability. Existing applications must consistently meet these requirements.
Which strategy is right for you depends not on trends, but on three factors: how critical the application is to your business, how high the risk of an incident is, and whether the effort is economically worthwhile. As a rough guide:
- High criticality, little time → Rehosting.
- Moderate complexity → Replatforming.
- Scalability and Future-Proofing Are Key → Refactoring.
- Significant technical debt → New development (→ Application Development).
- Low business relevance → Continue operations or shut down.
Not every application needs to be rebuilt from scratch. If it is not technically or economically feasible to modernize an application, building a new one from scratch is the better option.
Migration Alone Isn’t Enough—Where the Real Difference Lies
Modernization is strictly aligned with your business goals. The key factor is whether an application can be operated in a stable, secure, and cost-effective manner after the transformation. The following overview shows why many projects fail—and what really matters.
Where AI Is a Help - and Where It Isn't
Application landscapes are often complex, poorly documented, and closely intertwined. AI helps to make sense of this complexity more quickly. A recent Lünendonk study shows how IT decision-makers assess the potential of AI to varying degrees depending on their area of responsibility:
Source: Lünendonk, 2026
So there is still significant untapped potential, particularly when it comes to IT modernization. Arvato Systems uses AI where it actually saves time—in analyzing code and dependencies, in refactoring, in test automation, and in documentation and knowledge transfer.
Architectural and operational decisions continue to be made by the team of experts. After all, an application doesn’t modernize itself just because a language model has read the code.
Why AI Can't Work Without Modernization
Many applications are simply not AI-ready. They are built as monolithic systems, are difficult to integrate, and do not provide a clean data foundation. Modernization creates exactly this foundation: API- and event-driven architectures, secure data flows, and an application landscape that can support scalable AI applications.
Why Compliance Is Critical in Application Modernization
Security and regulation are at the top of the IT agenda: 92% of companies plan to invest more in cybersecurity over the next two years (Lünendonk, 2026). Application modernization is therefore also a compliance issue. This is because it’s not just code and architecture that are changing, but also aspects that, at first glance, seem to have little to do with technology: data flows, responsibilities, and operating models. That is precisely where the greatest risks arise.
Operational Challenges During Day-to-Day Operations
Data flows are changing due to the cloud, APIs, and the integration of new services, and responsibilities are shifting between providers and customers in line with the principle of shared responsibility. Existing systems are often not sufficiently auditable, so operational and emergency plans must be redesigned.
Regulatory Requirements
In regulated industries, the target vision cannot be achieved without addressing DORA, NIS2, and the GDPR: Security and access strategies are being reimagined—often based on the zero-trust principle—and business continuity is increasingly becoming a subject of audit itself.
Without these considerations, new risks arise—even if the technical modernization is successful. That is why Arvato Systems incorporates compliance, security, and operations from the very beginning—as early as Phases 1 and 2, when the course is set for the architecture and target vision.
Arvato Systems' Services for Your Modernization
How We Can Specifically Assist You with Modernization and Operations - All from a Single Source
Arvato Systems combines modernization and operations into a single model. Upon request, the organization that modernizes your applications will also continue to operate them afterward—around the clock. This is becoming increasingly important as IT landscapes become more hybrid: 34% of companies in Germany rely on hybrid cloud, and 38% on multi-cloud (Bitkom Cloud Report, 2026).
Built-to-Run means that we develop with long-term, continuous operation in mind from the very beginning, rather than considering operations, security, and FinOps only after go-live.
24/7 operation upon request: German-speaking core teams take over day-to-day operations upon request.
Industry experience: Practical experience in regulated industries such as financial services and energy.
Hybrid and multi-cloud expertise: on AWS, Microsoft Azure, and Google Cloud—as well as in our own data center.
What Specific Benefits You’ll Gain from Modernization
Economic added value through application modernization
- Innovation
Modernization enables new technologies and processes for more competitive advantages. - Fast market response
Adapt to market opportunities for faster business opportunities. - Efficient use of resources
Rationalization and optimization of technologies and processes as well as cost savings on maintenance costs - Improved compliance
Modernization simplifies the administration of regulations and saves time and costs. - Increasing productivity
Modern software enables efficiency and collaboration in teams. Cloud technology meets individual team requirements better than legacy systems.
Technical added value through application modernization
- Security
Improved security and stability for smoother operation. - Development speed
Faster provision of new functions for increased responsiveness. - Scalability
Adapt to increasing requirements without sacrificing performance. - Adaptability
Flexible adaptation to changing requirements and environments. - Improved user/customer experience
Efficient data entry, better project tracking and secure storage in the cloud contribute to high-quality customer support.
What This Means for Your Business in Practical Terms
You’ll quickly notice the difference: New features go live faster because teams deliver in shorter iterations rather than long release cycles. Systems run more smoothly—fewer disruptions, fewer overnight emergency call-outs. Operating costs become predictable rather than surprising, thanks to automation, better architecture, and FinOps. Compliance is easier to demonstrate because security was built in from the start. And teams once again have time for innovation instead of troubleshooting.
This doesn't make technical debt disappear overnight. But it does get smaller—and the budget becomes available again for what really matters.
Ready for the Next Step?
Start with a structured architecture and operations assessment: During an initial consultation, we’ll analyze your current situation, identify risks, and outline a realistic modernization strategy—with no obligation and tailored to your application landscape.
Frequently Asked Questions About Application Modernization
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What does app modernization mean for the cloud?
App modernization for the cloud means adapting and optimizing applications to better align them with cloud platforms and services. This can include migrating, redeveloping or customizing applications to maximize the benefits of cloud usage.
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How does my company benefit from app modernization for the cloud?
App modernization for the cloud offers your company scalability, cost efficiency, improved security, flexibility and access to the latest technologies. This can help to increase efficiency, reduce costs and improve competitiveness.
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How is the app modernization done?
App modernization can be carried out in various ways. This includes the migration of existing applications that are moved from local servers to the cloud. Another variant is the redesign/partial modernization of applications in which individual components are replaced. Applications can also be containerized to make them lighter and more portable. Complete new developments in the cloud are also possible. The choice of method depends on your specific requirements, goals and resources.
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How long does it take to modernize an existing app?
The duration of app modernizations depends on the scope and complexity of the system. In our assessments, we work with you to develop a timeline for the modernization. In most cases, however, modernization is possible during ongoing operations so that business processes can continue to run smoothly.
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Which technologies and platforms are used for modernization?
The technologies and platforms used are selected based on your specific requirements in order to create the best possible cost-benefit ratio. Thanks to Arvato Systems' broad expertise, we can utilize a wide range of solution options in both implementation and operation.
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How is the security of my app guaranteed during the modernization process?
Security by design is one of the core principles of our app modernization process. As part of the requirements analysis, potential risks are identified and then adopted as requirements in the implementation process.
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How does Arvato Systems support you in maintaining and updating my app after modernization?
Arvato Systems is an established IT service provider with experience in a wide range of industries and business areas. Thanks to our experience and our qualified employees, we are able to provide support in various roles even after the app modernization process. In addition to application management, in public and private cloud, we can also provide support with a wide range of implementation services.
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