Modernize existing software or develop new one?
By Kevin Kröger, Geschäftsführer, Software und Plattformbetrieb
A new development is not automatically cleaner and a modernization is not automatically cheaper. The decisive factors are technical fit, technical changeability, security situation, data migration, dependencies and the risk to ongoing operations. Often, gradual replacement is the most resilient route.
Which facts should be taken into account when making an architectural decision?
First, record the processes, interfaces, data sets, operational problems and functions that are no longer needed. Check whether source code, tests, documentation and knowledge are available. The AWS readiness assessment considers, among other things, strategic fit, functional and technical suitability, economic viability and digital readiness. This inventory is more important than a spontaneous decision for a new technology.
When is there more to be said for modernization?
Modernization is a good idea if the technical core continues to work and risks can be reduced in specific steps. Possible paths range from continued operation to replatforming to refactoring individual components. Stable interfaces, automated tests and observable operations create safe transitions. The benefit comes not from a modern name, but from shorter changes, fewer failures or lower operational risks.
When does a new development become plausible?
A new solution can make sense if central requirements can no longer be met, critical knowledge or source code is missing, changes can hardly be tested or the existing architecture blocks any further development. Even then, the old application should not be switched off in a single, uncontrolled change. Data transfer, parallel operation, fallback path and technical acceptance are part of a step-by-step migration plan.
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Frequently asked questions
- Is a completely new building always cheaper in the long term?
- No. Data migration, parallel operation, edge cases that need to be recreated and new operating processes can make a new building significantly more expensive. Both paths require a comparable overall cost and risk assessment.
- Can you modernize an application while it is still in operation?
- Yes, if changes are cut into small pieces, interfaces are checked, data paths are checked and fallback options are prepared. The appropriate path depends on criticality and architecture.