GDPR and Legacy Systems at a Glance

Our experience shows that many companies with legacy systems often stand at a crossroads. On the one hand, the old IT infrastructure is often business-critical; on the other hand, the topic of GDPR compliance is increasingly pushing into focus. By GDPR-relevant legacy systems, we mean IT landscapes that were developed before the General Data Protection Regulation came into force and therefore do not automatically meet all current requirements. They also often contain grown structures that have only been selectively extended or adapted over the years.

Such legacy systems make it difficult to identify, protect, and, if necessary, delete sensitive data. The data is usually stored in scattered formats, and a unified overview is often missing. This is precisely where the risk lies. According to the IBM 2024 Cost of a Data Breach Report, the average cost of a data breach now amounts to USD 4.88 million, which is further encouraged by inadequately maintained or unsecured legacy systems [1].

We also observe that the legal situation is not getting any easier. The EU and national data protection authorities continually apply stricter standards. Measures such as transport encryption (TLS) and end-to-end encryption (E2EE) have become almost indispensable as soon as personal data is transmitted via insecure channels [2]. Companies still working on outdated structures must retrofit to avoid fines or reputational damage.

A further aspect is the technical complexity. Legacy systems by no means exist only as isolated databases or mainframes but often interlock deeply with ongoing business processes and external systems. In a modernization project, we therefore must not interrupt operations and at the same time must meet legal requirements. A careful approach that keeps everything in view is decisive so that high costs and time delays do not arise in the end.

Recognizing Compliance Risks in Time

In outdated IT environments, we repeatedly encounter similar danger spots. One of the most frequent causes of security gaps is the absence of current patches. Especially when software manufacturers have ended support, the system remains vulnerable. If personal data is stored there, GDPR compliance is quickly endangered. Legacy systems also often suffer from missing logging. If an incident occurs, attackers may only be detected late, the damage grows, and forensic tracing becomes laborious.

Another problem is unclear ownership of the data. Who controls certain data flows, who may grant access rights? Legacy systems grow over years and undergo various organizational changes. Silos and opacity arise as a result. Companies acting with stopgap solutions risk implementing data protection measures with gaps. According to current studies, around one-third of CIOs in Europe and the USA are unable to find personal data within the set deadlines [3].

Compliance risks can also arise from missing deletion concepts. The GDPR provides that data subjects have the right to have their personal data deleted (right to be forgotten). In legacy systems, this data is often stored in primary keys or in archives that are barely captured by automated deletion routines. Data sets thus remain available for longer than allowed. Unencrypted media such as old backups on CDs or external hard drives also pose a risk [4]. For genuine compliance, it is not enough to record data protection policies in theory; they must be practically implementable.

Strategy for a Modern IT Landscape

To turn legacy systems back into a future-proof IT landscape, a consistent strategy is needed that takes both technical and organizational aspects into account. A structured roadmap is essential here. We usually start with a thorough inventory: which systems exist in what state, what data is collected, and where are the weak points?

After this analysis follow clear goal definitions with regard to GDPR compliance. It is important to us not just to meet the minimum requirements but to reach a level that facilitates future adjustments and growth. We therefore recommend integrating security concepts such as Zero Trust from the outset, establishing granular access protection, and using encryption technologies not only partially but consistently [5].

A modernization project can also often be divided into segments. So that we don't risk massive operational outages, we carry out partial steps in which defined modules or functions are migrated. The day-to-day business can run in parallel. This phased approach has proven itself, for example when we switch a complex mainframe application to a Linux or cloud infrastructure. The risk thus remains calculable, and employees can gradually familiarize themselves with new processes.

In this context, we support our clients in the search for financial funding opportunities, for instance through KfW funding for digitalization. Especially in the mid-market, such programs are an attractive option, since expenses for technology, personnel, and training can often be reduced. Decisive factors are precise project goals and transparent implementation plans. Once a modernization project is clearly outlined, the chances of public funding rise. Ultimately, this foresight pays off because the IT landscape is tidied up and existing systems run in a GDPR-compliant manner.

Carrying Out Data Migration Securely

One of the biggest hurdles in any modernization project is dealing with the existing data assets. When we talk about data migration, we face several challenges: first, we have to ensure that personal data is correctly recognized and classified. Second, integrity must be preserved during migration, so that no duplicates, inconsistencies, or deletion errors arise. Third, the data layer must be prepared in such a way that it fits into the newly planned system environment.

To minimize this risk, we rely on a combination of manual review and automated scans. Experts recommend the use of special metadata analysis tools, such as Orion Governance's Metadata Harvester, to track down hidden personal information [4]. Files and database entries are subsequently structured according to data protection criteria. This also includes the encryption of data at rest and in motion, so that no unauthorized access takes place.

If it turns out that old data records are no longer used or are long outdated, they should be deleted or anonymized using legally compliant procedures. We thus save ourselves future obligations and reduce the data volume. SCOOP Software recommends conducting test runs under realistic conditions before the actual go-live [5]. We thus check early on whether performance losses or compatibility problems arise. After a successful migration run with hypercare phase, remaining errors can be specifically eliminated.

Particularly important in data migration is documentation. We record in detail which data records were transferred, deleted, moved, or encrypted. This traceability is indispensable for a GDPR audit. Especially in industries with strict regulations (e.g. healthcare), incomplete documentation can lead to substantial fines. With well-founded logging, by contrast, we create transparency and strengthen trust with customers and partners alike.

Zero Trust in Legacy Environments

The Zero Trust approach pursues the principle of treating every access attempt neutrally and granting access to a system only after careful verification. Traditionally, companies assumed that everything happening inside the company network was trustworthy. Legacy systems were usually built such that they granted higher permissions on the intranet. But modern security concepts see it differently: every request is meticulously checked — regardless of whether it comes from inside or outside.

Especially in legacy systems where directory structures and access controls have grown historically, introducing a Zero Trust architecture is challenging. At the same time, it is enormously worthwhile. What's important here is a step-by-step implementation. We begin by segmenting the network environment: applications and databases are divided into security zones between which only approved data traffic may flow. This segmentation prevents an attacker who breaks into a legacy system from automatically compromising the entire network [1].

In addition, we recommend consistently using multi-factor authentication (MFA) and encryption to curb identity theft. We thus reduce the risk of legitimate access being misused. Centralized SIEM systems (Security Information and Event Management) help to identify suspicious activities in time, since they collect and correlate logs from various sources. As soon as we detect an unusual event, the security team can react before greater damage occurs.

For us it is clear that Zero Trust is a complex and long-term project. It encompasses the technological rebuilding of the architecture, but also a change in mindset across departments. Employees must learn why even an internal process is no longer blindly trusted and how to authenticate securely. The good news is that Zero Trust creates an excellent foundation for sustainable security and supports us in complying with the GDPR, because every data movement becomes precisely traceable.

Understanding Costs and Funding

Modernizing legacy systems can require significant investment. However, these costs can be put into perspective by several factors. First, a long-term secure and GDPR-compliant IT landscape directly impacts liability risk — a potential data protection violation can have extreme financial consequences. Second, a more efficient architecture reduces follow-on costs, for example through less maintenance effort and optimized processes. The profitability of such projects can be illustrated, for example, with metrics that we deal with in our article on IT modernization ROI.

In addition, there are state funding programs such as KfW funding for digitalization, which specifically support mid-sized companies in digital transformation. Such programs subsidize, among other things, consulting services, software licenses, or hardware investments. We advise checking early on which criteria must be met and how high the potential subsidies can be. Especially for IoT integration, security solutions, or automation processes, attractive funding scenarios exist.

A modernization project can also often be linked to important milestones in the company. If we plan the SAP ECC replacement 2027 at the same time, for example, we leverage synergies in system conversion. Likewise, the planned restructuring can be taken as an opportunity to redefine departmental boundaries or improve processes in sales and logistics. The result: greater efficiency, fewer data silos, and a more structured handling of personal information.

Anyone who relies quickly on the supposedly cheapest provider risks expensive rework in the long term. A solid evaluation of all offers, technologies, and service providers proves its worth. The respective expertise in GDPR and IT security should be a central decision factor. Because at the latest in a crisis, it becomes clear whether a partner has extensive know-how or merely operates superficially. In the end, holistic modernization usually pays off many times over for companies.

Practical Examples and Recommendations

To comply with GDPR requirements while modernizing the outdated IT landscape, promising models are already on the market. SCOOP Software, for example, develops modernization roadmaps that take into account both the technical and the data protection level [5]. There, in several phases, it is determined which legacy systems have priority, how data flows can be optimized, and which security measures take effect. After completed migration, such providers support a hypercare phase so that ongoing operations are stabilized.

Another example is TmaxSoft and its OpenFrame solution, which allows companies to migrate their mainframe applications to open environments [3]. There, COBOL code is translated into contemporary languages such as Java, and outdated interfaces are standardized. Such solutions help to streamline old data assets and transfer them to cloud or on-premises systems that better meet GDPR requirements.

Because every company has different priorities, no patent solution can be prescribed. What we keep emphasizing are these decisive steps:

• Thorough inventory of all systems, data, and interfaces
• Prioritization according to security risks and business-critical functions
• Selection of a competent partner with proven experience in GDPR contexts
• Step-by-step migration, supported by pilot projects and test runs
• Continuous monitoring and improvement to keep pace with new regulations

Such an approach protects against rushed quick fixes and forms the basis for a reliable, future-proof IT infrastructure. Everyone wins: the management, because fines and downtime are minimized; the employees, because they can work more efficiently with a modern environment; and ultimately the customers, whose data is best protected.

Comparison of Old vs. Modern (Example Table)

| Criterion | Legacy System | Modernized System | |------------------------------|------------------------|--------------------------------| | Data security | Rarely encrypted | Encrypted throughout | | Maintenance and support | Discontinued updates | Regular patches | | GDPR compliance | Often incomplete | Concept-based and audited | | Scalability | Heavily limited | Flexible (cloud, hybrid) | | Operating costs | High due to overhead | Tend to fall with SLA contracts|

This comparison shows that through modernization we not only mitigate legal risks but also gain economic efficiency in the long term.

Conclusion

We are firmly convinced that GDPR-compliant IT modernization goes far beyond a mere mandatory exercise. Anyone who tackles GDPR-relevant legacy systems lowers compliance risks, improves IT security, increases operational efficiency, and at the same time becomes more flexible for future requirements. A successful modernization process avoids the high fines or loss of reputation that can result from data protection violations.

In addition, the company gains new agility: when new business models are planned, for example, or further developments in customer data protection are required, the organization can react more quickly. This is precisely why decision-makers and budget officers in the mid-market should engage with these topics early on and examine the possibilities of modernization. It is worth taking a close look at additional efficiency potential, for instance through modernizing legacy systems in mid-market companies.

In conclusion, a thoughtful and comprehensive approach is the best foundation. Solid architecture planning, consideration of funding options, and cooperation with partners who combine technical and data-protection know-how usually lead to excellent results. Anyone who already takes IT compliance into view today will not only be more secure tomorrow but also more economically positioned.