We all know that every long-running business has that one system everyone secretly dreads using. It still “works,” sure, but it’s slow, clunky, and glued together with patches nobody remembers setting up. Keeping it alive costs more each year, and at some point, it stops being just an inconvenience, it holds the whole company back.
Modernizing those systems isn’t about chasing the newest buzzword tech. It’s about making sure the backbone of the business can handle how things actually run faster, more connected, and way more flexible than before. In Europe, there are teams that specialize in this exact kind of heavy lifting. They roll up their sleeves, get into the old code, and rebuild it into something that feels less like a museum piece and more like the engine of a modern company.
1. A-Listware
At A-Listware, we spend a lot of our time helping clients across Europe deal with older systems that no longer fit the way they work today. Many of the companies we support already rely on complex platforms, but those platforms weren’t designed to handle modern demands. Our role is usually to modernize what’s there, make sure it connects smoothly with newer tools, and do it in a way that doesn’t disrupt the daily work people depend on.
We also take on projects where modernization is part of a bigger digital shift. That can mean rebuilding parts of legacy applications, developing custom solutions, or helping clients move pieces of their infrastructure into the cloud. For us, it’s less about flashy changes and more about making sure the core systems are reliable, flexible, and able to keep up with how business runs today.
Key Highlights:
- Work with European clients across different industries
- Focus on modernizing existing systems instead of replacing everything
- Balance consulting with hands-on technical work
- Help organizations move to the cloud step by step
- Support long-term projects and ongoing maintenance
Services:
- Legacy system modernization
- Custom software development
- Application redesign and upgrades
- Cloud migration and integration
- Data and analytics solutions
- Ongoing support and system maintenance
Contact Info:
- Website: a-listware.com
- Email: info@a-listware.com
- Facebook: www.facebook.com/alistware
- LinkedIn: www.linkedin.com/company/a-listware
- Address: St. Leonards-On-Sea, TN37 7TA, UK
- Phone Number: +44 (0)142 439 01 40
2. Capgemini
Capgemini is one of those firms you bump into when a company has been running the same systems for years and finally needs to sort them out. In Europe, they’re often called in to deal with the kind of tech that’s too expensive to keep patching but too risky to just throw away. They look at what’s already there and figure out how to get it working with today’s tools without shutting everything down in the process.
Most of the time, their work isn’t about ripping out every system and starting fresh. They take a more practical route, updating the parts that can be fixed, linking old platforms with modern ones, and replacing only what’s really necessary. That way businesses can keep moving while the heavy lifting happens in the background.
Key Highlights:
- Works with both public and private sector clients
- Used to handling big, complicated IT setups
- Focus on updating what’s already in place instead of replacing everything
- Helps companies move forward without long interruptions
- Mix of consulting and hands-on technical work
Services:
- Legacy system upgrades and modernization
- Cloud migration and integration
- Application support and management
- Custom software development
- IT consulting for system transitions
- Cybersecurity and compliance services
Contact Info:
- Website: www.capgemini.com
- Phone: +33 1 47 54 50 00
- Address: Place de l’Étoile, 11 rue de Tilsitt, 75017 Paris, France
- LinkedIn: www.linkedin.com/company/capgemini
- Instagram: www.instagram.com/capgemini
- Facebook: www.facebook.com/Capgemini
3. Atos
Atos is one of those companies that often gets involved when large organizations need to bring old IT systems into the present. They work a lot in Europe, especially with industries that can’t just flip a switch and change everything overnight. Instead, they help untangle legacy setups, connect them with modern tools, and make sure the business can keep running while changes are happening in the background.
They’re also known for sticking around after the initial fixes are done. Rather than handing off a system and walking away, Atos tends to manage ongoing updates, migrations, and support. Their focus is usually on making sure complex systems stay reliable while slowly shifting them toward newer, more flexible setups that don’t hold the company back.
Key Highlights:
- Works with large organizations across multiple sectors
- Handles complex, long-running IT systems
- Focus on step-by-step modernization rather than full replacement
- Provides both consulting and technical support
- Active in many European markets
Services:
- Legacy system modernization
- Cloud migration and hosting
- Application support and management
- Cybersecurity and risk management
- IT consulting and system integration
- Infrastructure and workplace services
Contact Info:
- Website: atos.net
- Email: de-info@atos.net
- Phone: +49 89 541936006
- Address: Otto-Hahn-Ring 6, 81739 Munich Germany
- LinkedIn: www.linkedin.com/company/atos
- Twitter: x.com/atos
- Instagram: www.instagram.com/atosinside
- Facebook: www.facebook.com/Atos
4. Tietoevry
Tietoevry is a company that spends a lot of time dealing with the systems big organizations rely on but often struggle to modernize. In Europe, they usually step in when businesses have platforms that are still critical but clearly showing their age. Instead of pushing for a full replacement, they look for ways to make those systems run better, connect to newer tools, and stay useful without disrupting daily operations.
They also work on longer-term changes, not just quick fixes. Their projects often involve helping companies shift parts of their infrastructure to the cloud, update older applications, and improve how data moves across different systems. The idea is to make sure the IT foundation doesn’t get in the way of business changes, while keeping the transition steady and manageable.
Key Highlights:
- Works with both private companies and public organizations
- Strong presence across Europe
- Focus on making existing systems more adaptable
- Supports gradual modernization instead of sudden overhauls
- Mix of consulting and technical delivery
Services:
- Legacy system modernization
- Cloud migration and hosting
- Application development and support
- Data and analytics solutions
- System integration and consulting
- Cybersecurity services
Contact Info:
- Website: www.tietoevry.com
- Email: info@tietoevry.com
- Phone: +3582072010
- Address: Keilalahdentie 2-4 FI-02101 Espoo Finland
- LinkedIn: www.linkedin.com/company/tietoevry
- Instagram: www.instagram.com/tietoevry
- Facebook: www.facebook.com/Tietoevry
5. GFT
GFT is a company that usually gets involved when banks, insurers, or other large businesses need to move on from old systems that can’t handle today’s demands. A lot of their projects in Europe focus on taking legacy platforms and reworking them so they can integrate with modern digital tools. Rather than pushing a full rebuild from day one, they look at what can be reused, what needs upgrading, and how to make the shift without breaking day-to-day operations.
They also spend a fair amount of time helping companies get comfortable with cloud setups. That might mean migrating applications, redesigning workflows, or just making sure data and processes aren’t stuck in outdated systems. Their role is often about giving organizations a smoother path forward so they’re not trapped by older technology but also not overwhelmed by too much change at once.
Key Highlights:
- Works mainly with financial services and large enterprises
- Focus on modernizing older platforms without disrupting business
- Helps companies adopt cloud and digital solutions gradually
- Mix of consulting and technical implementation
- Active across several European markets
Services:
- Legacy system modernization
- Cloud migration and integration
- Application development and support
- Data and analytics solutions
- IT consulting and system integration
- Digital transformation projects
Contact Info:
- Website: www.gft.com
- Address: Am Belvedere 8 A-1100 Wien Vienna, Austria
- LinkedIn: www.linkedin.com/company/gft-technologies
- Instagram: www.instagram.com/gft_tech
- Twitter: x.com/gft_tech
- Facebook: www.facebook.com/gfttechnologies
6. Future Processing
Future Processing is a software company that often works with businesses looking to update systems that have been around a little too long. They usually get involved when organizations realize their older setups are slowing things down and making it harder to keep up with newer demands. Instead of pushing for a total rebuild, they focus on helping companies modernize piece by piece so the tech can actually support the way people work now.
They also take on projects where businesses want to build new features on top of what they already have. That might mean reworking legacy applications, improving integrations, or creating something fresh that plays nicely with older systems. Their approach is fairly practical: keep the important stuff running, update what’s outdated, and make sure the overall setup doesn’t hold the business back.
Key Highlights:
- Based in Poland with clients across Europe
- Works on updating older systems without full replacement
- Focuses on practical solutions that keep daily operations going
- Experienced with both new builds and legacy upgrades
- Mix of software engineering and consulting
Services:
- Legacy system modernization
- Custom software development
- Application redesign and upgrades
- Cloud integration and support
- Data and analytics solutions
- Ongoing software maintenance
Contact Info:
- Website: www.future-processing.com
- Email: sales@future-processing.com
- Phone: +48 32 461 23 00
- Address: Bojkowska 37a, 44-100 Gliwice Poland
- LinkedIn: www.linkedin.com/company/future-processing
- Facebook: www.facebook.com/FutureProcessing
- Instagram: www.instagram.com/futureprocessing
7. Siili
Siili is a Finnish company that spends a lot of its time helping businesses modernize and make sense of their digital systems. They’re often called in when older platforms have become a roadblock and need reworking to stay useful. Their style leans toward combining design with technical work, so modernization projects usually cover both how the systems run in the background and how people actually use them day to day.
They don’t just swap out old tech for new tools and walk away. Instead, they try to make existing setups more practical, easier to integrate, and ready for gradual change. That might mean reshaping a legacy application so it plays better with modern platforms, or moving parts of a system into the cloud without interrupting ongoing work. The goal is usually to give companies more flexibility without forcing an all-or-nothing rebuild.
Key Highlights:
- Based in Finland with a European client base
- Mixes technical modernization with user-focused design
- Works on making older systems compatible with modern tools
- Favors step-by-step upgrades over complete replacements
- Balances consulting with hands-on delivery
Services:
- Legacy system modernization
- Application redesign and development
- Cloud migration and integration
- Data and analytics projects
- UX and digital service design
- Ongoing support and maintenance
Contact Info:
- Website: www.siili.com
- Email: toni.petajamaa@siili.com
- Phone: +358 40 576 5315
- Address: Ruoholahdenkatu 21 00180 Helsinki Finland
- LinkedIn: www.linkedin.com/company/siili-solutions
- Facebook: www.facebook.com/SiiliSolutions
- Instagram: www.instagram.com/siilisolutions
8. ELCA
ELCA is a Swiss IT company that often works with organizations struggling to bring their older systems up to speed. A lot of their projects focus on making sure existing platforms don’t hold businesses back as they try to adopt newer tools and ways of working. Instead of forcing a complete overhaul, they usually help companies modernize in steps, so operations keep running while the background systems get upgraded.
They’re also involved in areas beyond just fixing old tech. ELCA often builds custom applications, integrates cloud services, and provides support for ongoing system changes. Their approach is fairly straightforward: keep what’s still useful, replace what isn’t, and make sure everything ties together in a way that feels less like patchwork and more like a working system.
Key Highlights:
- Based in Switzerland with clients across Europe
- Focus on step-by-step modernization of legacy systems
- Handles both technical upgrades and consulting work
- Works with a wide mix of industries
- Combines new builds with support for older platforms
Services:
- Legacy system modernization
- Cloud migration and integration
- Custom application development
- IT consulting and support
- Data and analytics solutions
- Cybersecurity and compliance services
Contact Info:
- Website: www.elca.ch
- Email: marketing@elca.ch
- Phone: +41 21 6132 111
- Address: Av. Général Guisan 70a, CH-1009 Pully Switzerland
- LinkedIn: www.linkedin.com/company/elca-informatique-sa-elca-informatik-ag
9. Adesso
Adesso is a German IT company that often ends up working with organizations trying to deal with older systems that no longer fit the way business runs today. Their projects usually involve figuring out how to modernize legacy setups so they can handle new demands without shutting everything down. It’s more about making gradual changes that keep things moving rather than ripping out entire systems and starting from scratch.
They also cover a wide range of tech work beyond just modernization. That includes building custom applications, moving parts of systems into the cloud, and making sure data flows properly between platforms. Their role is often about keeping IT infrastructure reliable while giving businesses space to adapt and grow with less disruption.
Key Highlights:
- Based in Germany with a European presence
- Focuses on updating legacy systems step by step
- Handles both consulting and technical delivery
- Works with public and private sector clients
- Combines modernization with ongoing system support
Services:
- Legacy system modernization
- Cloud migration and integration
- Custom software development
- Application support and management
- Data and analytics solutions
- IT consulting and system integration
Contact Info:
- Website: www.adesso.de
- Email: info@adesso.de
- Phone: tel:+4923170007000
- Address: Adessoplatz 1 44269 Dortmund
- LinkedIn: www.linkedin.com/company/adesso-se
- Twitter: x.com/adesso_SE
- Instagram: www.instagram.com/adesso_se
- Facebook: www.facebook.com/adessoSE
10. NNIT
NNIT is an IT services company that often gets pulled into projects where older systems are holding things back. They usually work with organizations that need their legacy platforms updated so they can keep up with modern requirements. Instead of forcing a complete restart, NNIT tends to focus on making those systems more secure, easier to maintain, and able to connect with new technologies.
They also handle plenty of work beyond just modernization. That includes cloud migrations, application support, and consulting to help companies figure out how to balance day-to-day operations with longer-term changes. Their role is often about making sure IT doesn’t get in the way of business goals while setting up a smoother path for future upgrades.
Key Highlights:
- Strong focus on regulated industries like healthcare and finance
- Works on securing and updating legacy platforms
- Combines modernization with ongoing system support
- Provides both technical delivery and consulting
Services:
- Legacy system modernization
- Cloud migration and hosting
- Application development and support
- IT infrastructure management
- Cybersecurity and compliance services
- Consulting for digital transformation
Contact Info:
- Website: www.nnit.com
- Email: nnitcontact@nnit.com
- Phone: +4570244242
- Address: Weidekampsgade 14 DK-2300 Copenhagen S
- LinkedIn: www.linkedin.com/company/nnit
- Twitter: x.com/nnit
- Facebook: www.facebook.com/NNITGroup
- Instagram: www.instagram.com/nnit_group
11. PA Consulting
PA Consulting is a UK-based firm that tends to get involved when organizations need more than just technical fixes. They don’t just look at the old systems and figure out how to patch them up, they also step back and consider how the technology lines up with the bigger picture of how the business works. That means their modernization projects often mix strategy with the hands-on task of dealing with outdated platforms.
They usually work with companies that are in the middle of complex changes, whether it’s moving to the cloud, rethinking processes, or trying to connect legacy systems with new digital tools. The approach is rarely about ripping everything out and starting again. Instead, they guide businesses through gradual updates while keeping things running, so the organization doesn’t lose momentum in the middle of big transitions.
Key Highlights:
- UK-based with clients across Europe and beyond
- Focus on both technology and business strategy
- Works with organizations going through major change
- Mix of consulting and technical modernization
- Known for step-by-step updates rather than big-bang replacements
Services:
- Legacy system modernization
- Digital transformation consulting
- Cloud migration and integration
- Process redesign and improvement
- Application development and support
- Cybersecurity and compliance advisory
Contact Info:
- Website: www.paconsulting.com
- Phone: +44 28 9073 6779
- Address: 4th Floor Printworks 35-39 Queen Street Belfast, BT1 6EA Northern Ireland
- LinkedIn: www.linkedin.com/company/pa-consulting
- Twitter: x.com/PA_Consulting
12. Luxoft
Luxoft is a global IT services company that often gets called in when businesses need help modernizing older systems. They usually work with big organizations where legacy platforms have become too clunky to keep up with current needs. Their role is often about figuring out how to connect those outdated systems with newer technologies while keeping the day-to-day work running.
They also do quite a bit of custom development, especially for industries like finance, automotive, and healthcare where systems tend to be complex and critical. That might mean building new applications, moving parts of existing platforms to the cloud, or just improving the way different systems talk to each other. The aim is usually practical: make sure IT supports the business without becoming a bottleneck.
Key Highlights:
- Works across multiple industries including finance, automotive, and healthcare
- Focus on modernizing legacy systems without full replacement
- Known for handling complex, large-scale IT setups
- Combines consulting with hands-on technical work
- Active across Europe and globally
Services:
- Legacy system modernization
- Custom software development
- Cloud migration and integration
- Application support and management
- Data and analytics solutions
- IT consulting and system integration
Contact Info:
- Website: www.luxoft.com
- Phone: +39 011 1987 24 48
- Address: Via Nizza 262/56, Turin 10126 Italy
- LinkedIn: www.linkedin.com/companies/luxoft
- Twitter: x.com/Luxoft
- Facebook: www.facebook.com/Luxoft
13. Sii
Sii is a Polish IT services company that usually works with businesses trying to keep older systems from holding them back. They get involved when companies realize that the tech they’ve been running for years just doesn’t fit with today’s demands anymore. Their role is often about updating legacy platforms, making them work with newer tools, and helping organizations move toward more modern setups without pulling the plug on everything at once.
They also handle a wide range of software projects, not just modernization. That includes custom development, application management, and cloud integration. A lot of their work is about keeping the core systems stable while slowly introducing improvements, so companies don’t get stuck between outdated infrastructure and overly complicated replacements.
Key Highlights:
- Based in Poland with a European client base
- Focuses on upgrading and modernizing existing systems
- Balances technical work with consulting support
- Works across industries from finance to manufacturing
- Supports gradual transitions instead of full replacements
Services:
- Legacy system modernization
- Custom software development
- Cloud migration and integration
- Application management and support
- IT consulting and system integration
- Data and analytics solutions
Contact Info:
- Website: sii.pl
- Email: contact@sii.pl
- Phone: +48 22 486 37 37
- Address: Metron building, 1st, 2nd, 3rd and 7th floor al. Niepodległości 69 02-626 Warszawa Warsaw Poland
- LinkedIn: www.linkedin.com/company/sii-polska
- Instagram: www.instagram.com/siipolska
- Facebook: www.facebook.com/Sii.Polska
14. Reply
Reply is an Italian-based group of companies that work across Europe helping organizations sort out their IT systems. They often get pulled in when businesses are stuck with a mix of older platforms and newer tools that don’t really connect. Their job is usually to modernize what’s already there, make systems talk to each other, and ensure day-to-day operations don’t grind to a halt while changes are being made.
They’re spread across different specialist units, which means one team might be focused on cloud projects while another works on application development or data solutions. That setup gives them flexibility to handle different types of modernization work. At the core, though, it’s about making IT infrastructure less of a bottleneck and more of a support for how businesses actually want to run.
Key Highlights:
- Based in Italy with offices across Europe
- Works through specialized units with different focuses
- Deals with legacy upgrades and system integration
- Covers a wide range of industries and clients
- Balances consulting with technical delivery
Services:
- Legacy system modernization
- Cloud migration and integration
- Application development and support
- Data and analytics solutions
- IT consulting and system integration
- Cybersecurity and compliance support
Contact Info:
- Website: www.reply.com
- Phone: +44 (0) 207 730 6000
- Address: 160 Victoria St 2nd floor Nova South Westminster London SW1E 5LB, UK
- LinkedIn: www.linkedin.com/company/reply
- Twitter: x.com/Reply_UK
- Facebook: www.facebook.com/ReplyinUK
Conclusion
Modernizing legacy systems in Europe isn’t a one-size-fits-all job. Some companies focus on gradual fixes, others handle full rebuilds, and plenty sit somewhere in between. What they all share is the understanding that outdated tech can’t be ignored forever, it has to evolve if businesses want to stay competitive.
The good news is there’s no shortage of teams ready to take on that work. Whether it’s a large consultancy guiding a step-by-step transition or a smaller firm digging into custom upgrades, the options are there. The smart move is to start with the areas that cause the most friction and see how modernization can ease the load. From there, it’s usually easier to keep moving forward.
