Services
Excel to app
An internal application instead of shared spreadsheets. Stock, orders, attendance or approvals in one tool, accessible over the web.
Services · Legacy system rescue
We migrate the old system nobody understands anymore
For companies whose operations run on MS Access, Excel macros or old PHP, and the person who built it is no longer around.
What you are dealing with
The author has left and nobody knows how it works
The Access database or Excel macros were written years ago by a colleague or contractor. Today nobody wants to touch them.
Every change is a risk
Fixing one thing breaks another. Changes take a long time and nobody can say what else they will affect.
The system holds back growth and security
It does not work over the web, cannot handle several users at once, runs on an unsupported version, and backups are a matter of luck.
Which systems we migrate
Most often these are tools that were once built quickly and then became the core of the business:
- MS Access databases: records of orders, customers or stock, often with forms and reports.
- Excel files with VBA macros: calculations, quotes, exports and reports that “only one person knows how to run”.
- Old PHP applications: internal systems written years ago, without tests and on an unsupported version.
- Other internal tools that have lost both their documentation and their author.
Why in stages
Rewriting the whole system at once and switching over one day is the riskiest possible route. If something is forgotten, you find out only in live operation. That is why we split the system into parts. We migrate each part, verify it with the people who work with it daily, and only then switch off the original version.
Before rewriting each part, we prepare tests that compare the results of the old and new systems on the same data. That way you can be sure the calculations, totals and reports match.
Throughout the migration you know which phase the project is in, which part already runs in the new system and what is left. Users get the new system in smaller batches, so they do not have to learn everything at once and have time to point out things the old system did “on the side” that nobody ever wrote down.
If your system is mainly a spreadsheet you want to turn into an application, take a look at our Excel to app service as well.
What you get
- Audit and map of the existing system, its data and dependencies
- List of risks and what happens if nothing changes
- Migration plan in stages without operational downtime
- New application replacing the original system piece by piece
- Data transfer from the old system, with checks
- Technical and user documentation
- Handover to your team or another vendor
How it works
weeks 1–2
Audit and mapping
We go through the code, database, macros and dependencies, and talk to the people who use the system every day.
week 3
Migration plan
We plan the order of stages so that operations keep running. The old and new systems can run side by side for a while.
in stages, usually weeks to months
Step-by-step rewrite
Each stage is deployed and verified with users, and only then do we switch off the matching part of the old system.
final week
Handover and documentation
We hand over the code, documentation and operating procedures. Someone other than the author will be able to understand the system.
Who it is for
- Companies whose operations depend on MS Access, VBA macros or old PHP
- Systems that nobody in the company can safely change
- Situations where the original author has left or stopped responding
- Companies that cannot stop operations to replace a system
Who it is not for
- Systems that work and have an active maintainer with documentation
- Companies that only want a quick fix of one bug with no further plan
- Projects where the system can be replaced by off-the-shelf software
Why work with us
We understand the old and the new
Michal Czerník manages the full SDLC from analysis to operations. He can read the old system, design the new one and make sure no data or logic is lost along the way.
Risk management from leading teams
Experience leading development teams and in the CTO role means a staged plan, verification with users and no big overnight switch.
AI speeds up reading unfamiliar code
With AI-assisted development in Claude Code we map unfamiliar code faster and prepare tests that confirm the new system calculates the same way as the old one.
Frequently asked questions
Do operations have to stop during the migration?
No, we plan the migration in stages so that operations keep running. The old and new systems can run in parallel for a while.
How long does a migration take?
The audit and plan usually take three weeks. The length of the rewrite depends on the size of the system and is set based on the audit.
Will we lose data from the old system?
No, data transfer is part of every stage. After the transfer, we check the data against the original system.
Can you handle a system with no documentation at all?
Yes, that is exactly what we expect with legacy systems. We create the documentation from the code, the data and interviews with users.
Can the old system just be fixed instead of rewritten?
Sometimes yes, and the audit will show it. If a fix is the cheaper and safer route, we recommend it.
What is VBA?
VBA (Visual Basic for Applications) is the macro programming language in Excel and Access. Many internal business tools still run on it.
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Free consultation
Tell us what you are working on. We will get back to you and arrange a short call to see whether and how we can help.