Modernize software

When this service helps

Modernize software: your brief for us.

Replace discontinued technologies
Make changes predictable again
Preserve knowledge from legacy applications

Where applications have been running for years on outdated frameworks, we modernize them step by step with a planned changeover. After an inventory of code, dependencies and data flows, we choose the path for each application: replatforming into containers, refactoring into modules, data migration to a new model or replacement with a successor application. Old and new parts run in parallel until the last process has moved over.

What the assignment can include

Inventory with code analysis, dependency list, data flows and operating costs per application
Evaluation by business value and risk, decision between replatforming, refactoring and replacement
Characterization tests around the legacy code base before the first line is changed
Gradual decomposition using the strangler pattern, running old and new parts in parallel
Data migration with reconciliation, trial run and documented fallback plan

We define the specific scope, acceptance points and your involvement in the proposal.

The context at a glance

Understand the existing system. Master the transition.

01
Capture
Make business logic and dependencies visible
02
Secure
Test existing behavior so it can be compared
03
Switch over
Control data ownership and cutover
04
Retire
Decommission old components in an orderly way

Planning, implementation and decisions

What matters for Modernize software.

01

Understand before replacing

Source code often contains business rules that no document fully describes. That is why we combine code and dependency analysis with conversations in the business unit and observation of real workflows. Recurring incidents, manual corrections and edge cases show where the actual risks lie. We also capture data sources, background jobs and external callers.

Characterization tests record how the application works today. Not every existing behavior is correct; business logic errors are explicitly separated from functions that must be preserved. This creates a solid basis for comparing the old and the new system.

02

Renewal in controllable steps

Moving to a new platform does not automatically solve problems in the application code. We therefore distinguish between changes to the runtime and operations, rebuilding individual modules and complete replacement. Where it makes sense, a new component gradually takes over tasks from the existing system. Parallel operation is a planned transition phase with clear data ownership.

Each step gets a goal, a test scope and a fallback decision. Maintenance windows and possible interruptions are planned jointly; uninterrupted operation is not a blanket promise. The next part is only switched over once evidence for the respective process is in place.

03

Data migration and controlled decommissioning

Historical data contains duplicates, missing values and rules from earlier versions. We define mapping, cleansing and reconciliation before the production migration. Trial runs show whether run times, data volumes and exceptions are manageable. Particularly important totals, relationships and samples are checked from a business perspective.

Before shutdown, exports, retention, questions about legacy cases and dependent systems must also be clarified. We document which data remains available where and when a fallback is no longer possible. The handover includes the new operations documentation as well as how the decommissioned system is handled.

For business owners and technical teams

The decisions behind the implementation.

04

Preserving business behavior instead of blindly porting legacy code

In legacy systems, the code often explains only part of the process. Spreadsheet exports, manual data corrections and scheduled jobs may have taken over indispensable tasks. We capture these side paths and build up a catalog of characteristic cases: normal cases, historical exceptions, boundary values and known defects. A comparison run between the old and the new system makes deviations visible, but does not yet decide which result is correct from a business perspective.

The business unit evaluates differences together with the development team. Rounding, time zones, sort order or historical pricing rules can create seemingly small deviations with a major impact. Intended behavior changes are separated from unintended regressions. Only then is there a meaningful basis for acceptance. The documented cases later serve as a lasting safety net for further changes and preserve knowledge that, until now, only individual people have held.

05

Planning data ownership during parallel operation and cutover

As long as old and new components work together, responsibility for write access must not be unclear. For each data domain, we designate one system of record and plan the handover of this responsibility. Two applications writing without coordination can create contradictory states, even if each one works correctly on its own. The interim architecture therefore needs its own interfaces, reconciliations and a limited lifetime.

A migration plan covers the initial load, interim changes and the final reconciliation. We check record counts, business totals, relationships and representative individual cases. Before the cutover, abort criteria, decision authority and permitted write pauses are defined. A fallback is only realistic if newly created data can be processed again. Where that is not possible, the point in time and the consequences of this limit are stated before approval.

06

Technical decoupling and completing the replacement

A new user interface placed on top of an unchanged legacy architecture does not automatically remove its limits. We examine shared tables, implicit file formats, direct database access and libraries that tie several applications together at once. Adapters introduced step by step can absorb changes. However, they are transitional components with their own maintenance needs and should not quietly become a permanent second system landscape.

That is why every replaced function also has a decommissioning task. Old jobs, user accounts, interfaces, infrastructure and licenses are checked for remaining use. Historical inquiries may require read-only access or a documented export. The modernization of this stage is complete only once dependencies are resolved, operations documentation is updated and responsibilities have been handed over. This prevents the costs of the old and the new system from permanently adding up.

Results you can verify

What you take away.

Result 01

Evaluated application portfolio with a modernization path per application

Result 02

Modernized application with test coverage and container images

Result 03

Migration record with data reconciliation and fallback plan

Example project flow

This is what the engagement can look like.

A billing system runs on a runtime that is no longer supported. First, calculations are secured with comparison tests. This is followed by a clearly scoped module; the data migration is rehearsed multiple times before the production cutover is approved.

Illustrative scenario, not a customer reference or a guarantee of results.

This helps you get started

Source code and an executable test environment, where available
Known defects, dependencies and critical deadlines
Functional test cases and points of contact for historical rules

Missing documents are not an obstacle. We work out together which information needs to be gathered first.

Your project in detail

Modernize while the business keeps running.

We plan the renewal of existing applications with a view to their business significance. The scope can range from a targeted technical upgrade to the gradual replacement of individual functions.

Safeguard existing behavior before making changes

Documentation alone rarely describes every rule of an application that has been used for years. We gather representative cases, exceptions and known errors together with your users. Suitable comparison tests record which behavior must be preserved and which deviations should be deliberately corrected.

A technical inventory and business prioritization are combined. Outdated libraries, modules that are hard to change and frequent operational disruptions have different impacts. We choose the starting point where benefit, risk and dependencies allow a controlled stage.

Design transitions and data ownership explicitly

During a period of parallel operation, it must be clear which system is authoritative for which data. Uncontrolled writing on both sides can create conflicting states. We plan synchronization, transition adapters and reconciliation only for the transition period actually needed.

A fallback path depends on the data changes already made. That is why, before the switch, we define how long a return remains possible and what rework it would require. After a successful transition, old access, tasks and infrastructure are decommissioned deliberately, so that the interim solution does not permanently add complexity.

Illustrative project scenario

How the service helps in everyday use.

Example: An existing application is to gain a new customer area. We first extract the read-only customer view and compare its data with the legacy system. Write operations follow later, with a defined switch of data ownership.

This example explains a possible process and is not a customer reference.

Before you place an order

Your questions about Modernize software.

Does everything need to be redeveloped?

No. Business logic that works well can be preserved. The inventory shows whether a runtime change, the renewal of individual modules or a replacement makes sense. What matters is maintainability, risk and the planned changes to the business process.

What happens if documentation is missing?

We reconstruct relationships from code, data and actual workflows. Employees with subject-matter knowledge are especially important in this process. Missing access or usage rights can limit the scope; such gaps are clarified before we give a firm commitment.

Can operations continue in the meantime?

The changeover can often be carried out in stages. Whether parallel operation, short maintenance windows or a longer interruption is needed depends on data storage and architecture. We plan the cutover with business-level reconciliation and a realistically usable fallback path.

Useful combinations

Software consulting Custom software Web portals & apps Develop interfaces Software testing DevOps & releases Software maintenance

The next step

Tell us where things are stuck today.

A short description of your application, the problem and your goal is enough to get started. The selected service is carried over into your contact request.

Request this service

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