What counts as a legacy system?

Any application based on a technology that is no longer actively supported or is outdated - e.g. PHP 5.x/7.x, Java 8 or older framework versions like Magento 1, Typo3 v8 or Spring 3. We also treat systems without CI/CD pipelines, without containerization or with undocumented infrastructure as legacy.

Do you touch the application code?

Not during the stabilization phase - we work exclusively at the infrastructure and configuration level. Code changes only happen during the modernization step and only in coordination with your development team. We document everything and ensure your team understands the code at all times.

How long does modernization take?

Stabilization and containerization typically takes 2-4 weeks. Full modernization using the strangler fig pattern is a continuous process that can take 3-12 months depending on complexity - your application remains available throughout.

What does the cost structure look like?

Stabilization is delivered as a fixed-price project. Ongoing operations (monitoring, patching, backups) are billed as a monthly flat rate. Modernization projects are calculated by effort or as sprint-based fixed prices - always transparent and predictable.

Do you also take over systems without documentation?

Yes - that is the rule rather than the exception. A structured inventory is a fixed part of the takeover: we catalog servers, services, dependencies and access credentials, document the setup and close the gaps left behind by the predecessor. In the end there is documentation your team can work with again.

What if there are no more updates for our system?

Then we harden the environment around it: network segmentation, a reverse proxy in front of the application, restrictive firewall rules and close monitoring. Honestly, a residual risk remains that cannot be fully eliminated without upstream patches - which is why we always recommend a concrete modernization path in parallel.

Can you move legacy systems into VMs or containers?

Yes. We virtualize physical servers via P2V migration and encapsulate suitable applications in containers. Both are proven stabilization steps: a reproducible environment, clean backups and easier maintenance, without touching the application code. As a virtualization platform we rely on Proxmox VE.

What does legacy operations cost?

That depends on risk and effort: age of the stack, criticality, state of documentation and desired response times. That is why we calculate individually after a short assessment. Entry via pure monitoring is available from €49.90 per server and month.

Operate and incrementally modernise legacy applications

WZ-IT stabilises older PHP, Java, .NET, and Python applications, assumes a clearly defined operational scope, and plans required modernisation as a separate incremental path.

PHP
Java
.NET
Python

Assess legacy application Take over unknown servers

Reviews

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Companies worldwide trust WZ-IT

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Operations and modernisation

Stabilise production operations and reduce technical debt separately

Ongoing operations are scoped by application, versions, dependencies, and recoverability. Upgrades, containerisation, or redevelopment are separate project components and are not presented as an unspecified part of the operations contract.

Legacy application operations
Monitoring, updates within a viable scope, backup management, documentation, and incident triage for the existing stack.
Take over an organically grown server estate
When access, documentation, or system condition are unclear, the process starts with inventory and a server audit before an ongoing contract.
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Technologies

Technologies We Support

From classic PHP monoliths to Java enterprise applications - we know the quirks of older stacks and keep them running reliably.

PHP
Magento, Shopware, WordPress, Typo3
Java
Spring, Tomcat, JBoss
.NET
.NET on Linux
Python
Django, Flask, Plone

Process

Our Approach

Three phases - from immediate stabilization to long-term modernization.

01
Stabilize
Secure & Monitor: We secure the existing system, connect it to our 24/7 monitoring, and close critical security gaps without jeopardizing ongoing operations.
02
Containerize
Docker / Podman: Isolate the application in containers for reproducible deployments, easier maintenance and independent scaling of individual components.
03
Modernize
Incremental Migration Path: Step-by-step migration using the strangler fig pattern: new features in modern stacks, legacy components are gradually replaced.

Included Services

What's Included in Operations

All services that ensure stable and secure operation of your legacy application.

Monitor

Runtime Monitoring
24/7 monitoring of availability, performance, and resource utilization.
Log Analysis
Central log aggregation, error tracking and proactive anomaly detection.

Maintain

Security Patching
Regular security updates for OS, runtime and dependencies.
Dependency Updates
Updates for libraries, frameworks and runtime environments.

Optimise & protect

Performance Optimization
Analysis and tuning of database queries, caching and response times.
Backup & Recovery
Daily backups with tested restore processes and retention policies.

Modernization

Modernization Path

No big-bang rewrite, but controlled, step-by-step evolution of your application.

Strangler Fig Pattern

Reduce big-bang risks through staged migration
Make new functionality available early
Run old and new components in a controlled parallel phase

Scope boundary and notes

The strangler fig pattern enables gradual replacement of a legacy system: new features are developed in a modern stack while existing functionality is progressively migrated. The old system remains operational throughout - it is not shut down but replaced piece by piece.

Containerization

Reproducible builds & deployments
Independent of host OS and versions
Easier scaling and portability

Scope boundary and notes

Containerization with Docker or Podman decouples your legacy application from the infrastructure. This simplifies maintenance, enables reproducible deployments and makes a later move to modern platforms significantly easier.

Legacy Stacks

Typical Legacy Stacks We Take Over

The same principle applies in every case: stabilize, secure (as far as possible without upstream patches), document and map out a realistic modernization path.

PHP 5.x / 7.x applications
Shops, CMS and custom applications on PHP versions without security support. We stabilize operations, isolate the application and map out the path to PHP 8.x.
Java 8 / Tomcat
Spring and Tomcat applications on old JDKs. We harden the configuration, monitor the JVM and document the migration path to a current LTS release.
.NET Framework
Applications on the classic .NET Framework. We keep operations stable, document dependencies and map out the path to modern .NET.
Ubuntu / Debian / CentOS EOL
Servers on releases without vendor support. We secure them as far as possible without upstream patches - for example through segmentation and monitoring - and plan the migration to supported versions.
MySQL 5.x
Databases on MySQL 5.x. We verify backups, keep operations stable and prepare the upgrade to MySQL 8 or MariaDB.
Inherited Docker hosts
Undocumented container setups from a predecessor or external provider. We inventory images and compose files, document the setup and establish an update process.

Frequently Asked Questions

Answers to the most important questions

Guides

Further guides

These services complement legacy operations.

Complementary services

Relevant next steps

Reviews & projects

Operations that visibly relieve customers

Customer feedback on monitoring, updates, maintenance, support and stable production systems.

Networking & Provisioning

WZ-IT moved our studio infrastructure from decentralised individual devices to a central platform: every site is securely connected via VPN, new devices are onboarded automatically and an entire site is provisioned from a template, without manual steps on location. What impressed me most is the breadth and depth of their knowledge: Timo and Robin are not a typical IT provider who sets up a server and leaves. The two of them think their way into highly complex infrastructure and software topics, work through every requirement we put in front of them, and build networking, provisioning and operations so that everything fits together in the end. WZ-IT is an excellent partner for complex software, network and architecture projects.

Steve KirchnerManaging Director, nextGYM GmbH

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International

Built in Germany's Ruhr Valley. Running worldwide.

WZ-IT designs, develops and operates infrastructure and software for clients in Germany and internationally. We deliver projects remotely and continue supporting them in ongoing operations after go-live.