Legacy modernization: renew old software step by step
The application has run for years, but hardly anyone dares to touch the code any more: the original developer is gone, and the PHP version or the framework is outdated. Sortia Labs takes over such systems, secures operations first and then modernizes in small steps instead of rebuilding everything at once.
- Legacy modernization
- Replace old software
- PHP migration
- Replace Access
- Code audit
- Old systemKeeps running
- InterfaceOld and new talk to each other
- Module by moduleSmall, tested steps
- New architectureDocumented and maintainable
What modernization includes
Code audit and inventory
We read the code, the database and the server setup, find outdated libraries with known vulnerabilities and document what the system actually does. You get a list of risks in a clear order.
Step-by-step replacement
We replace the old system piece by piece: new parts take over single functions while the rest keeps running until it is replaced as well, an approach known as the strangler pattern.
PHP and framework upgrades
From PHP 5 or 7 to PHP 8, and from outdated frameworks to maintained versions. Along the way we replace functions that are no longer supported and swap out dependencies whose development has stopped.
Moving the data
From Access, old MySQL versions or file shares into PostgreSQL or MySQL, with checksums and counts that show every record has arrived. Trial runs beforehand make the moving day predictable.
Containers and automated delivery
The modernized application runs in Docker and is built, tested and delivered through GitHub Actions. Updates become a planned routine instead of a weekend job.
Keeping the knowledge
Business rules often live only in the old code. We write them down as documentation and tests, so they survive the change and your team can look them up later.
Modernizing while the system stays in use
- 1
Risks first
First we fix what puts operations at risk today: missing backups, open vulnerabilities, a server without updates. Only then does the actual rebuild begin.
- 2
A safety net of tests
Before we change any code, automated tests record how the application behaves today. Every later change is measured against them, even where no documentation exists.
- 3
Rebuild in stages
Function by function moves into the new structure. Old and new run side by side for a while, and we switch over only once the new part has proven itself.
- 4
Switch off the old
When all functions have moved, we archive the old data in a traceable way and switch off the old system. What remains is an application your team is glad to work on again.
Questions about Legacy modernization
Rewrite or modernize?
A complete rewrite usually takes longer than planned and loses rules that existed only in the old code. That is why we usually recommend step-by-step modernization. A rewrite makes sense when the platform itself has reached its end, for example with old Access applications.
Do you take over applications whose developer is no longer available?
Yes, especially those. The code audit gives us the overview; then we collect access and knowledge while someone in the company still has it, and take over operations and further development step by step.
Does operation continue during the modernization?
That is what the approach is designed for: switching happens in small steps at times you help decide, and every step has a planned way back. Where a short interruption cannot be avoided, such as when moving the database, we announce it in advance and rehearse it.
Which legacy systems do you modernize?
Mainly web applications in older PHP, Java applications and Access databases, plus the databases behind them such as MySQL and PostgreSQL. The goal is an architecture with current PHP 8 or Python, clean interfaces and Docker, depending on what your team can maintain in future.
How do we know it is time to modernize?
Typical signs: updates are postponed because their effects are hard to judge, small changes take weeks, only one person still knows the system, or the host announces the end of the old PHP version. Then an audit is worthwhile before an outage forces the decision.
Read on.
Show us your legacy application.
Briefly describe what it does, what it runs on and what worries you. We suggest an audit as the first step and tell you openly whether modernizing or rebuilding makes more sense.