Legacy Application
Modernization Services
Trusted by

Legacy application
modernization services we provide

AI-native legacy application modernization services for mission-critical systems that can’t afford downtime. We modernize enterprise-scale applications with near-zero disruption, preserving the business logic and data your operations depend on.
icon-nav

Application migration and cloud-native rebuild

icon-nav

Application re-engineering

icon-nav

Application re-architecting

icon-nav

Re-platforming

icon-nav

Infrastructure modernization

icon-nav

Mainframe modernization

icon-nav

SaaS transformation

icon-nav

Containerization and Kubernetes

icon-nav

Database modernization and data migration

icon-nav

DevOps / CI-CD enablement

icon-nav

Legacy software maintenance

icon-nav

Technical-debt & cloud-readiness assessment

icon-nav

Multi-system consolidation

Application migration and cloud-native rebuild
icon-card

App migration and cloud-native rebuild

Move your app to AWS, Azure, or GCP and rebuild it to take advantage of cloud-native services for better scale and lower cost. We’re here to assist you in planning and executing the optimal cloud migration strategy. We will help you choose and execute the right path to the cloud — whether that’s a straightforward lift-and-shift, a replatform, or a full rebuild into cloud-native architecture. Execute it in phases with no long outages and no data loss. Cut infrastructure costs and boost performance with Euristiq’s cloud migration engineering.

icon-card Workload assessment and cloud-fit evaluation (AWS, Azure, or GCP)
icon-card Right-strategy selection: rehost, replatform, or re-architect to cloud-native, chosen per workload
icon-card Phased, wave-by-wave migration execution with rollback capability at every stage
icon-card Data migration with integrity verification — zero data loss
icon-card Monolith-to-microservices decomposition for true cloud-native rebuilds
icon-card Post-migration performance and cost optimization
View cloud migration services read more
Application re-engineering
icon-card

Application re-engineering

Re-engineer your legacy application at the code and architecture level to cut technical debt and improve performance. We restructure code and reduce architectural coupling using AI-assisted analysis and refactoring to move faster and catch risk earlier, then verify every change with automated regression testing. Gain a cleaner, more maintainable system preserving original scope and improving reliability.

icon-card Code-level refactoring for maintainability, performance, and readability
icon-card Architecture-level re-engineering that reduces technical debt without downtime risk
icon-card AI-assisted code analysis and refactoring to accelerate the process
icon-card Automated regression testing to confirm production behavior stays unchanged
icon-card Dependency mapping to prioritize the highest-impact areas first
icon-card Updated documentation reflecting the new code and architecture
Application re-architecting
icon-card

Application re-architecting

Redesign your application’s structure for better flexibility, scalability, and independent deployability, breaking a monolith into independent, individually scalable microservices. We map service boundaries around real business domains, extract services incrementally so the system keeps running throughout, and design the API contracts each service needs to communicate cleanly with the rest.

icon-card Monolith-to-microservices decomposition
icon-card Incremental, phased service extraction
icon-card Business logic mapping and preservation
icon-card Service boundary and API contract design
icon-card Independent deployment pipeline setup per service
icon-card Post-decomposition stabilization and refinement
Re-platforming
icon-card

Re-platforming

Move your application to a modern runtime or platform without a full rewrite – just enough changes to take advantage of what the new environment offers. This might include switching to a cloud-native database, changing the underlying OS, containerizing the app, or adopting platform-specific services, while keeping your core application logic intact.

icon-card Runtime and platform environment upgrade
icon-card Database migration to cloud-native equivalents
icon-card Containerization of application components
icon-card Adoption of platform-specific managed services
icon-card Configuration and dependency updates for the new environment
Infrastructure modernization
icon-card

Infrastructure modernization

Modernize the underlying infrastructure your application runs on – compute, storage, and network foundation – even when the application itself doesn’t require changes. We right-size compute resources, move storage to modern, cost-efficient tiers, and rebuild network architecture using infrastructure-as-code.

icon-card Compute resource right-sizing and modernization with rollback readiness
icon-card Network architecture redesign and infrastructure-as-code implementation
icon-card Storage tiering and migration to cost-efficient solutions
icon-card Infrastructure monitoring and automation setup
Mainframe modernization
icon-card

Mainframe modernization

Update and transform your legacy mainframe systems by migrating data to the cloud and developing cloud-native applications on the mainframe, to align with current and future business demands.

icon-card Mainframe workload analysis to identify offload, refactor, or integration opportunities
icon-card Controlled decomposition and integration layer development
icon-card Incremental modernization preserving transactional integrity and processing/reporting accuracy
SaaS transformation
icon-card

SaaS transformation

Turn your on-premise product into a multi-tenant, subscription-based cloud SaaS, lowering your total cost of ownership. We rebuild the architecture for true multi-tenancy, add subscription billing and self-service onboarding, and re-platform for elastic cloud scaling.

icon-card Multi-tenant architecture design and tenant data isolation
icon-card Self-service onboarding and account provisioning
icon-card AI-first architecture shift
icon-card Subscription billing and metering integration
icon-card Elastic, multi-tenant infrastructure setup
View SaaS development services read more
Containerization and Kubernetes
icon-card

Containerization and Kubernetes

Containerize your legacy applications to standardize deployment, improve isolation, and enable controlled scaling across cloud and on-premises environments. We package applications and dependencies into portable containers and set up Kubernetes-ready deployment models with the governance your release process needs.

icon-card Containerization of legacy runtimes with consistent, isolated environments
icon-card Kubernetes-ready deployment models
icon-card Controlled scaling and release governance setup
Database modernization and data migration
icon-card

Database modernization and data migration

Migrate and modernize your legacy databases – moving from outdated, on-premises systems to modern, cloud-native platforms – with full data integrity, lineage, and zero data loss verified at every step.

icon-card Legacy database assessment and migration planning
icon-card Data migration to cloud-native database platforms
icon-card Data integrity and lineage verification
icon-card Schema modernization and optimization
DevOps / CI-CD enablement
icon-card

DevOps / CI-CD enablement

Automate your build, test, and deployment pipelines to release faster with less risk. We set up CI/CD pipelines aligned with your change management and audit needs, with release automation that includes traceable approvals, rollback mechanisms, and environment-level controls.

icon-card CI/CD pipeline setup aligned with change management
icon-card Release automation with traceable approvals and rollback mechanisms
icon-card Environment-level access and deployment controls
View DevOps services read more
Legacy software maintenance
icon-card

Legacy software maintenance

Keep your systems running smoothly after modernization. Our legacy software maintenance service includes routine updates, bug fixes, and performance optimizations, ensuring your systems remain robust and updated without requiring a complete overhaul.

icon-card L2/L3 technical support and incident resolution
icon-card Routine bug fixes and security patching
icon-card Performance monitoring and tuning
icon-card Scheduled maintenance and update cycles
Technical-debt & cloud-readiness assessment
icon-card

Technical-debt & cloud-readiness assessment

Before committing to a full modernization plan, evaluate the real state of your applications. We provide the service of quantifying your technical debt and mapping the cost and risk of continuing as it is. The next step is assessing whether and how your apps should move to the cloud, including a total cost of ownership model to support the business case.

icon-card Technical debt quantification across code, architecture, and infrastructure
icon-card Risk assessment for carrying current systems forward
icon-card Cloud-readiness evaluation per workload
icon-card Total cost of ownership (TCO) modeling
icon-card Prioritized modernization roadmap recommendation
Multi-system consolidation
icon-card

Multi-system consolidation

Bring multiple overlapping systems (duplicate CRMs, ERPs, or legacy tools accumulated through growth or acquisition) onto one modern platform. Our team finds out what each system actually does, identifies redundant and conflicting functionality, and migrates the business logic and data your teams depend on into a single, unified platform without disrupting the operations running on the old ones.

icon-card System and tool inventory across the current platform landscape
icon-card Redundant and overlapping functionality mapping
icon-card Data and business logic migration to the consolidated platform
icon-card Phased cutover with legacy systems running in parallel until fully retired
icon-card Integration and workflow re-mapping for consolidated processes

What sets us apart
as legacy modernization company

01

AI-native delivery — 2× faster

AI runs through our 4D process, not just the products we ship: discovery, architecture, code, and testing. Same dedicated team, roughly half the timeline and cost.

02

Modernization without the rewrite gamble

We start with an audit that prices the risk — what your legacy system costs to keep, what it costs to change, and a phased path that front-loads quick wins.

03

One dedicated team, start to launch

A small cross-functional team owns your product from engagement through launch. No handoffs, no rotating faces, no re-explaining your business.

0100

Trusted. Certified. Awarded.

About us

Euristiq started in 2016 with a small team who kept running into the same problem: businesses stuck on systems too expensive to maintain and too fragile to change. Ten years and 300+ delivered projects later, that’s still what we fix.

Headquartered in Canada with delivery teams in Poland and Ukraine, we’re an AI-native legacy modernization firm. AI isn’t a service line we bolted on; it’s how we discover, re-architect, and re-build — which is why our 4D approach (Discover–Decide–Design–Deliver) delivers 2× faster and cheaper than traditional development.

For us the tech is never the label — the business pain is. Every engagement starts with what’s costing you money, time, or customers, and ends with software that measurably changes it.

10 +

Years on the market

For more than a decade, we’ve been building and modernizing business-critical software solutions
347

Projects delivered

Across legacy modernization, custom software, cloud transformation, and AI-adoption initiatives
10 /10

NPS score

Our customer satisfaction rate based on the 2026 questionnaire across all clients
2 x

Faster development

With an AI-powered software development approach, our clients save time and money

Hire trusted legacy modernization company

ISO 27001:2022 certified. AWS Advanced Tier Services Partner.
CASE STUDIES

Clients success stories

What our clients say

Euristiq provides top-tier developers that deliver high-quality output, which has supplemented a successful, multi-project partnership. Their work on the website contributed to performance improvements and boosted conversion and revenue rates.
Devid VP of tech at Ryanair, Euristiq's client
David O’Callaghan
Director, Software development
Dublin, Ireland
Euristiq has facilitated a successful partnership by providing highly qualified, knowledgeable, and ambitious resources. They accommodate internal project management preferences, such as working in sprints and using Azure DevOps, and remain flexible to working with different teams and technologies.
Andrew Dobson, CTO Octopus Investments, Euristiq's client
Andrew Dobson
Cheif Technology Officer
London, United Kingdom
Their ability to complete and manage the project efficiently was impressive. Modernized software provided up-to-date data for millions of luminaires, achieving outstanding quality through Euristiq’s robust testing methods and cohesive designs. The team’s helpful suggestions, organized scheduling, competitive pricing, and collaborative discussions exceeded expectations.
Euristiq's client, software development
Technology Manager
We engaged Euristiq a little over 12 months ago to build a bespoke UI on top of our marketplace platform, whose native UI did not meet the client’s expectations for UX and branding. They have exceeded my expectations throughout the engagement and are, by far, my best delivery centre in terms of on-time performance, quality, application performance, and professionalism.
Robert, Euristiq's client
Robert Emery
VP, Solutions
Toronto, Canada
0100

Industries we serve

Financial services & banking

Open banking / API enablement
Fraud detection & compliance modernization
Regulatory reporting system upgrades
Digital banking channel modernization
Core banking / mainframe modernization

Energy

IoT data platform
Asset management
Predictive maintenance
Digital twin platform
Field service management
Renewable energy management
SCADA/ICS integration

Healthcare

EHR modernization
HL7/FHIR interoperability
PACS/imaging system migration
Legacy lab & billing integration
HIPAA-compliant architecture

Logistics & supply chain

TMS modernization
WMS modernization
Fleet & telematics integration
EDI & carrier integration
Real-time visibility platforms

Insurance

Policy administration system (PAS) modernization
Claims processing automation
Underwriting system modernization
Core insurance system integration
Legacy data migration

SaaS vendors with aging products

Multi-tenant re-architecture
Monolith-to-microservices migration
Legacy codebase discovery & documentation
Subscription & billing modernization
SOC 2 / compliance readiness

Manufacturing

ERP–MES–SCADA integration
MES modernization
IIoT / OT-IT integration
Predictive maintenance enablement
Industry 4.0 readiness

Telecom

OSS/BSS modernization
Billing & revenue management systems
Network-as-a-Service enablement
Legacy CRM integration
API-first, TM Forum-aligned rebuild

Energy & utilities

SCADA / grid management modernization
Smart meter (AMI) data integration
Distributed energy resource (DER) integration
OT/IT convergence & cybersecurity
Legacy hardware emulation (SCADA platforms)

Government & public sector

Citizen portal / digital services modernization
FedRAMP / NIST / FISMA compliance
Cross-agency data integration

Our legacy application modernization roadmap

We are well aware that when modernizing a live legacy application, dependencies are real, compliance is active, and downtime has a cost. We choose the right mix of rehosting, replatforming, refactoring, rearchitecting, or rebuilding for each part of your system, then execute it in four phases built around your reality.
01

Legacy app assessment

AI-assisted analysis of client’s needs, codebase, dependencies, architecture and technical debt, resulting in a clear cloud-readiness assessment.
AI-assisted code and dependency analysis
Technical debt assessment
Cloud-readiness evaluation
Discovery-phase findings report
02

Strategy & roadmap

Selecting the right modernization approach, then mapping technology choices, budget, sequencing, and a risk mitigation plan into one roadmap.
Modernization approach selection, per component
Technology stack decisions
Budget and timeline planning
Risk management planning
03

App modernization

Executing a phased delivery with legacy and modern components running in parallel, backed by AI-assisted refactoring and automated test generation.
Phased delivery, legacy and modern systems running in parallel
AI-assisted refactoring
Automated test generation
Documentation and stakeholder review
04

Testing and post-modernization optimization

Testing integrations, security, failover, and performance under real-world load, followed by a near-zero-downtime cutover with rollback, and AI-driven monitoring after launch.
Testing beyond feature parity: integrations, security logs, failover, real-load performance
AI-generated regression testing
Near-zero-downtime cutover with rollback capability
AI-driven post-launch monitoring after launch
Modernize your mission-critical applications with a dedicated legacy software modernization company by your side

Go from outdated
to outstanding

FAQ

What does legacy modernization mean?

Legacy modernization means updating an existing outdated application – its code, architecture, or infrastructure – so it keeps running the business logic the organization depends on, so that it could scale, integrate, and stay secure. It’s not a rebuild from scratch; it’s evolving what already works instead of replacing it entirely.

How do I know it’s time to modernize?

The signs are usually financial and operational before they’re technical: maintenance costs spiking faster than the ability to ship new features, integrations that take months instead of weeks, frequent outages, and a shrinking team of people who understand the system. If any of that sounds familiar, it’s already time.

What are the common approaches to modernization?

Most modernization work falls into one of a few strategies: rehosting (moving as-is), replatforming (light changes for a new environment), refactoring (cleaning up code without changing behavior), rearchitecting (restructuring, often to microservices), or a full rebuild. The correct choice isn’t the same for every system – even within one application, different components often need different approaches.

What are the typical cost ranges, typical timelines, and what should I look for in a modernization partner?

Cost and timeline depend heavily on which approach a legacy app needs – a lift-and-shift can take weeks, a full re-architecture can take a year or more, and industry data shows the average large modernization program runs about 16 months. Rather than name a random number, we evaluate cost around our client’s system’s complexity, compliance needs, and chosen business strategy. When choosing a partner, look for a track record with systems as complex as yours, a phased delivery approach, transparent reporting, and AI approach that is both cost-efficient and responsible.

How does Euristiq use AI in legacy modernization?

AI supports our engineers at every stage – analyzing code and dependencies during assessment, accelerating refactoring and test generation during migration, and monitoring for issues after launch. Every AI-assisted output is meticulously reviewed by our team before it ships; we don’t treat AI as a replacement for engineering, just a way to move faster without cutting corners.

    Attach file
    We will add your contact details provided in this form to our system for contacting you regarding your request. For more info please consult our Privacy Policy
    Contact euristiq team

    Let’s talk!

    Ivan Muts, CEO of Euristiq
    Contact euristiq custom software development company