Top Legacy System Modernization Firms

Many core systems still run on COBOL, Visual Basic, old .NET or Java monoliths that few engineers can maintain and that cannot connect to modern tools. Legacy system modernization companies replace or rework them without stopping the business: they assess the codebase, choose between rehosting, refactoring, rearchitecting and rebuilding, then migrate data and users in stages. Companies hire them when vendors end support, when the last developer who knows the system is retiring, when security audits flag unsupported software, or when a new product needs APIs the old system cannot offer.

Compare the firms here on modernizations of your specific technology and on how they keep the old and new systems running side by side during the switch.

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We evaluate companies on verified profile data: services, pricing, locations, and portfolio. Client reviews are being collected. We may earn a fee for some placements. How we rank and verify

4,482 Companies

List of the Best Legacy System Modernization Agencies

Global Pioneers
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Our fundamental expertise in engineering and development enables us to provide innovative, cutting-edge, and reliable methods in the areas listed below:
Highlights
$50-99/hr
Avg Hourly Rate
2-9
Employees
Slate Hill, New York, Us
Services Provided+6 Services
20% E-Commerce Development
14% Legacy System Modernization
5% Other IT Consulting and SI
7% Custom AI Chatbot Development
AI Summary
“Global Pioneers excels in engineering and development, delivering innovative, reliable solutions across multiple disciplines with advanced methodologies and expertise.”
Instil
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Instil is a software engineering consultancy located in Belfast that assists technology firms worldwide in speeding up their delivery through tailored product engineering and developer training. Established in 2005, we offer a range of services, including custom development, cloud migration and mode
Highlights
$50,000+
Min Project Size
$100-149/hr
Avg Hourly Rate
50-249
Employees
Belfast, Northern Ireland, Gb
Services Provided+2 Services
33% Cloud Consulting & SI
17% Custom Web Application Development
10% Mobile App Development (iOS & Android)
7% Legacy System Modernization
AI Summary
“Instil is a Belfast-based software consultancy providing tailored product engineering, cloud modernization, and developer training to global technology firms, fostering innovation and digital transformation.”
Adapptor
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Whether we’re developing a new mobile app from scratch or enhancing your software team, our extensive experience ensures your future success. We have a proven track record of transforming businesses using mobile app technology, covering areas from enterprise logistics and mobile e-commerce to artifi
Highlights
$100,000+
Min Project Size
$150+/hr
Avg Hourly Rate
10-49
Employees
Perth, Western Australia, Au
Services Provided+3 Services
20% Mobile App Development (iOS & Android)
3% QA & Software Testing
3% Custom Web Application Development
7% Legacy System Modernization
AI Summary
“Adapptor specializes in developing and enhancing mobile applications with expertise in iOS, Android, AI, and AR, delivering customized, evolving software solutions for business success.”
Acceleanation
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TDT Consultants assists clients worldwide in maximizing the potential of their information systems within the manufacturing, logistics, and retail industries. We stay updated on the latest technologies, lean manufacturing practices, and project management methods, helping you understand, contextuali
Highlights
$10,000+
Min Project Size
$50-99/hr
Avg Hourly Rate
10-49
Employees
Montevideo, Montevideo, Uy
Services Provided+2 Services
23% ERP Consulting and SI
10% IT Staff Augmentation
20% Custom Web Application Development
14% Legacy System Modernization
AI Summary
“TDT Consultants delivers integrated business management solutions, leveraging latest technologies and lean practices in manufacturing, logistics, and retail to maximize information system value globally.”
Mylaensys
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Mylaensys offers consulting services to clients looking to implement Cloud Computing delivery capabilities for designing, constructing, and deploying infrastructure, platforms, and software as a service. By leveraging cutting-edge technology alongside creativity and expertise, Mylaensys delivers hig
Highlights
$5,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
2-9
Employees
Valley Cottage, New York, Us
Services Provided
50% Cloud Consulting & SI
25% Custom Web Application Development
15% Mobile App Development (iOS & Android)
10% Legacy System Modernization
AI Summary
“Mylaensys delivers expert consulting in cloud computing, designing and implementing innovative infrastructure, platforms, and software solutions tailored to diverse client needs with over 15 years' IT experience.”
MyProgrammer
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MyProgrammer is a tailor-made software development firm focused on Microsoft technologies. We offer solutions for web, mobile, and databases, with a strong emphasis on continuous maintenance and support. Established by industry expert Rob Carr in 1996, MyProgrammer collaborates with businesses natio
Highlights
$1,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
10-49
Employees
Services Provided
50% Custom Web Application Development
35% Mobile App Development (iOS & Android)
15% Legacy System Modernization
AI Summary
“MyProgrammer specializes in custom Microsoft technology software solutions, providing development, maintenance, and support for web, mobile, and database applications since 1996.”
Eleven36 HQ
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We create and develop secure, scalable digital platforms for dynamic businesses that are operating on a large scale. Collaborating with teams, we transform intricate needs into dependable, future-oriented technology, covering everything from fundamental systems and infrastructure to consumer-facing
Highlights
$5,000+
Min Project Size
$50-99/hr
Avg Hourly Rate
50-249
Employees
Services Provided
50% Custom Web Application Development
35% Mobile App Development (iOS & Android)
15% Legacy System Modernization
AI Summary
“Eleven36 HQ specializes in building secure, scalable digital platforms that transform complex business requirements into reliable technology, spanning core systems, infrastructure, and consumer-facing products.”
GCX Solutions
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With over 20 years of experience in executive-level software design and product management, I offer human-centered leadership through a distinctive approach that merges product management, design thinking, and technical expertise. This results in a highly effective process that enhances your revenue
Highlights
$1,000+
Min Project Size
$50-99/hr
Avg Hourly Rate
San Mateo, California, Us
Services Provided+1 Services
25% Custom Web Application Development
15% Mobile App Development (iOS & Android)
10% Legacy System Modernization
30% Product Design
AI Summary
“GCX Solutions delivers human-centered software development, UX/UI design, and product management services, empowering diverse industries with innovative, award-winning solutions and fractional leadership expertise.”
Kol3 SAS
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At Kol3 SAS, we operate as a digital solutions provider specializing in custom development. Our focus is on delivering tools for all types of businesses, offering straightforward solutions designed to create the perfect product.
Highlights
$1,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
2-9
Employees
Services Provided
50% Custom Web Application Development
35% Mobile App Development (iOS & Android)
15% Legacy System Modernization
AI Summary
“Kol3 SAS specializes in custom digital solutions, delivering tailored tools to diverse businesses with straightforward approaches that ensure creation of optimal products across industries.”
Saigon Technology
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Saigon Technology is a prominent custom software development firm with headquarters in Ho Chi Minh City and Da Nang, Vietnam. Founded in 2012, we boast a team of over 400 skilled software engineers and a robust development process. We have branches in Reston, Virginia (USA), Australia, Switzerland,
Highlights
$10,000+
Min Project Size
$25-49/hr
Avg Hourly Rate
250-999
Employees
Vn
Services Provided+3 Services
20% Software Development Services
20% Mobile App Development (iOS & Android)
20% Custom Web Application Development
10% Machine Learning Model Development
AI Summary
“Saigon Technology is a leading Vietnamese custom software development firm with global offices, offering agile, ISO-certified outsourcing solutions across diverse industries, including banking, healthcare, and retail.”

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Top Legacy System Modernization Firms

List of the Best Legacy System Modernization Agencies

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