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Legacy systems


Legacy systems are older software or hardware systems that are still used in a company or organization but are based on outdated technology. These systems are often difficult to maintain, expand, or integrate with modern technologies, but they continue to perform critical business functions.


Legacy systems are typically the result of long periods of use and rapid progress in information technology, which means that modern systems become obsolete. Despite their technological obsolescence, many of these systems are still in use due to their reliability, specific adjustments and the high costs or risks of upgrading.

Areas of application

Legacy systems can be found in almost all industries, but particularly in those that have grown over long periods of time, such as banking, insurance, manufacturing, and public administration. They are frequently retained because they support critical business processes.


The main advantage of legacy systems is their proven reliability in specific application contexts. They typically contain valuable historical data and specialized functions that are difficult to transfer to newer systems.


The challenges of dealing with legacy systems include security risks, lack of compatibility with new software, high maintenance expenses, and difficulties with integration into modern IT infrastructures. Strategies to overcome these issues include gradual modernization, using middleware to integrate, and training professionals to maintain old systems.


A typical example is a manufacturing company that continues to use an outdated ERP system because it is deeply integrated with the company's process control and logistics. Although the system is no longer state of the art, it is essential for daily operation.


Legacy systems are a double-edged sword in the IT landscape: They offer proven functions and stability, but pose a risk due to their outdated technology and difficult maintainability. The decision to replace or modernize them requires careful consideration of costs, benefits, and risks.