Legacy Software Modernization for the next stage of your application.
We deliver legacy software modernization for companies evolving an existing application. We assess the code, data and integrations, then refactor, re-engineer or rebuild the parts needed for your product and operating requirements.
- 120+Projects delivered across 12 countries since 2012
- 100+Senior in-house engineers, six countries
- 5.0Unified rating across 61 client reviews on Clutch
- AWS CertifiedSolutions Architects on the team
- ISO 27001Certified security practice, audited by Quay Audit UK
- ISTQBISTQB-certified QA engineers
01Overview
Decide what to retain and what to modernize
We start legacy application modernization by deciding what to retain, what to change and how the parts depend on each other. The assessment gives you a written roadmap for the application changes.
- Priorities grounded in the systemWe assess business value, technical debt and dependencies together. The roadmap explains the proposed sequence and the risks that affect it.
- An interface between old and newFor an incremental approach, the seam is the interface between a new module and the retained system. We assess whether those parts can coexist and design their data exchanges.
- Business behavior guides the changeYour product and domain owners identify the rules and workflows the application must preserve. We use those requirements to guide implementation and acceptance testing.
- Three routes besides a rebuildAn assessment can recommend maintaining it, a re-host focused on infrastructure, or AI integration on the existing application. The recommendation follows the change you need.
02Proof
Modernization you can verify
A clearer codebase matters when it supports useful changes to the product. Clients have reported easier maintenance, improved performance and operational gains in our client reviews.
- Booked It: rebuilt, then audited by someone elseWe refactored the booking platform onto Laravel, with React.js in the build, and ran its AWS migration after the client approved the plan. In his 2022 review, Brad Nobbs described a third-party code audit as "extremely complimentary" of the work.19%increase in bookings on average on the platform we rebuilt
- Continued engineering on an established SaaS platformWe joined the development of a US B2B SaaS platform with more than a decade of operating history. In his 2024 review, Patrick W. credited our PHP, AWS and Heroku experience and described a smooth transition into the work.30%+lower AWS costs than the previous setup
- Rental tracking connected to the operationFor a paddle sports operator, we built rental equipment and client tracking connected to the waiver system and MINDBODY APIs. In his 2017 review, Garrett Kababik attributed the revenue gain to efficiency and more accurate time tracking.15-20%increase in revenue, attributed to efficiency gains and accurate time tracking
03Compare
Rebuild, keep it maintained, or rewrite in one go?
Choose the approach around the application's future role, its dependencies and the change you need. A re-host addresses infrastructure; application modernization changes the software itself. A packaged product is also worth assessing when it can meet your workflow and integration requirements.
| Incremental modernizationunicrew | Keep it maintainedMaintain | Big-bang rewriteRewrite |
|---|---|---|
| Best forUseful business logic that can be retained while separable components evolve, with feasible interfaces between old and new. | Best forAn application that meets its intended requirements and needs continued upkeep. Software maintenance and support covers fixes, updates and operational improvements. | Best forA replacement whose scope, dependencies and data transition can be understood and validated as a whole. |
| What it asks of youPriorities and acceptance decisions for each phase, plus coordination of shared data, interfaces and releases while the systems coexist. | What it asks of youOngoing prioritization, access and an upkeep budget, with periodic review of support status and future product needs. | What it asks of youA defined replacement scope, validation of required behavior, and an operational plan for data migration and the final transition. |
| You end up owningModernized components and retained software, with their interface and handover responsibilities defined in the engagement. | You end up owningThe existing application with the fixes, updates and documentation included in the support scope. | You end up owningA replacement application with its acceptance criteria, transfer terms and ongoing support defined in the contract. |
Quick self-check
Tick what is true for you. The read-out updates as you go.
0 of 4 true
Start with maintenance and support
If the application meets your product needs, software maintenance and support can keep its updates and improvements moving. For an infrastructure change, assess a cloud migration. Modernization can also prepare for future requirements before they become urgent.
Talk it throughAssess the affected component
One requirement gives the assessment a clear starting point. We trace its code and data dependencies to decide whether a focused change is sufficient or whether the scope reaches further.
Talk it throughSettle the order before you budget the rebuild
Related requirements may share the same data layer or integration boundary. The assessment identifies those dependencies so the proposed sequence supports the changes you need.
Book a discovery callAssess the application as a whole
Several areas of change call for a view across the application. We assess which parts can be retained, whether phased coexistence is feasible, and how a replacement would affect your operations.
Book a discovery callBuild a roadmap across the dependencies
The assessment needs both technical and domain input when code, data access, support status and business rules all need attention. We use that context to recommend an approach and phase the work around operational requirements.
Start with the auditSome platforms are ready for AI as they stand, and others need modernizing first. Our audit settles which before we touch the code. Where modernizing comes first, we rebuild one module at a time until the platform is AI-ready.
Tural MamedovChief Executive Officer, unicrew04Capabilities
Application changes we deliver
We modernize the layers of a legacy system that need to change, from business logic and interfaces to data and deployment. The assessment defines which work belongs in your programme.
- Legacy application re-engineering
Application re-engineering
One module at a timeWe re-architect or rebuild selected components, or a complete application where replacement fits the requirements. A legacy web rewrite included a complete server and code rewrite using .NET Core, React and Stencil.js.
- Code refactoring services
Code refactoring and technical debt
Structure, not behaviorWe restructure code around the behavior it must preserve and test the affected paths. Data architecture can need a separate change: a multi-factor authentication platform used a re-architected data layer with horizontal sharding across database nodes.
- Legacy cloud re-platforming
Cloud re-platforming
Containers and infrastructure as codeWe update application runtimes and deployment configurations where the modernization calls for cloud re-platforming. A hotel booking programme used Microsoft Orleans, Docker, Terraform and Azure queues alongside changes to its integrations.
- Legacy data migration
Data migration and clean-up
Migrated, then reconciledWe map source and target data, implement the migration and reconcile the results against defined criteria. Your data owners help settle business rules, exceptions and which system holds authoritative records during the transition.
- Legacy API modernization
Integration and APIs
Clean, documented APIsWe rebuild interfaces, document their contracts and test the connected workflows in scope. Integration design accounts for the ERP, CRM, payment services and other systems that exchange data with the application.
- Legacy security remediation
Security hardening
Dependencies, encryption, access controlWe update unsupported dependencies and remediate prioritized findings in encryption and access control. Verification records the changes made, the tests performed and any findings that need further action.
- Legacy interface rebuild
UI/UX modernization
Mapped onto your component setWe rebuild selected interfaces around your component set and test the workflows users depend on. A training software platform engagement mapped legacy UI implementations to the client's existing new components, with preserving functionality as its goal.
- Legacy system audit
Software audit and roadmap
The code, the data, the integrationsWe inspect the code, data model and integrations against your requirements, then document the recommended approach, sequence and risks. Our guide to legacy application modernization challenges explains the dependencies an assessment needs to address.
05Trust
What a modernization hands over
We define the roadmap, interface records and transition documentation in the engagement scope, with ownership and handover terms in the contract. There is no minimum engagement period.
- In writingThe module order, and the reasoning under itYours to act on, in the order and at the pace you choose
- ContractedHow the old system and the new module talkStill standing after the cut-over, because whatever is still legacy keeps talking through it
- CurrentWhat has moved, and what is still on the legacy pathThe register a takeover has to reconstruct when nobody kept one
06Stack
Stacks we modernize, and modernize onto
We assess the legacy stack and select target technologies around application behavior, data, integrations and deployment requirements. We work across existing and replacement stacks, from WebForms modules to .NET Core with Vue JS.
React
Vue JS
.NET Core
C#
Java
PHP
Laravel
Yii2
MS SQL
MySQL
AWS
Azure
Docker
Terraform
WordPress07Engagement
How a modernization engagement is shaped
You can commission an assessment before deciding on implementation. After it, the work can proceed as a scoped module or through a dedicated team under your day-to-day direction.
Audit first, then decide
Start hereWe assess the code, data and integration surface, then produce a written roadmap with the proposed approach, phases and dependencies. The assessment has its own agreed scope and deliverable.
- Best when
- You need to choose an approach and define the application changes
- You pay
- Outcome based, quoted per project
- Typical start
- Two to four weeks
A dedicated modernization team
Long-runA dedicated team implements the modernization under your day-to-day direction. We agree the required skills and coordination, with knowledge transfer and any ongoing support defined for the engagement.
- Best when
- You have an ongoing modernization roadmap and direct the team's work
- You pay
- Billed monthly, per team member
- Typical start
- Two to four weeks
One module, scoped
Fixed scopeAfter assessment, we define a component's implementation, interfaces, data work, testing and cutover criteria as a fixed scope. That gives you a bounded piece of application change to commission.
- Best when
- A component can be specified and accepted independently
- You pay
- Outcome based, quoted per project
- Typical start
- Two to four weeks
Assess the completed work and the remaining transition
We map what has been built, what remains on the legacy path and how the parts exchange and reconcile data. The written assessment recommends which work to finish, revise or stop, and what the next delivery phase requires.
08Industries
Where legacy modernization pays off
We plan application changes around the workflows and data rules of your sector. Those rules guide what must be preserved, tested and accepted when a component changes.
Logistics and transportation
We evolve lead management, quoting, orders and billing. A SaaS platform for a US moving company was built from scratch and then changed as its market evolved. A separate vehicle-logistics engagement supported an operator whose case history records inventory and inspections on 9M+ vehicles.
Hospitality and leisure
We modernize booking workflows and their connected systems. Work includes an adjustable booking platform refactored onto Laravel and a hotel booking platform with updated IBS Software and Shift4 connections alongside its containerized cloud stack.
E-commerce
We rebuild commerce interfaces and product, order and ERP integrations. A client-led programme for a European scented-products manufacturer re-platformed off WordPress onto Shopify storefronts, with custom middleware connecting Microsoft Dynamics. Its case describes sales across seven EU countries.
Accounting and fintech
We develop financial workflows around their records and access requirements. A financial advisory engagement used MySQL, ASP.NET MVC and C# to automate bookkeeping tasks, recording information in the backend and matching it against invoices.
Automotive
We re-engineer service applications for the way workshops and operators use them. A vehicle-maintenance service tool moved from a desktop application to a multitenant cloud SaaS platform, with a newly designed SaaS architecture.
Healthcare
We improve monitoring workflows, interfaces and data integrations. A home health monitoring platform programme combined stabilization, a UI/UX redesign and new data integrations with lower AWS operating costs. The client's 2025 review names .NET and TypeScript in the work.
Scope the next stage of your application
Tell us what you want the application to support next, and what needs to stay in service. We discuss the system, its dependencies and the assessment needed to define the changes.
What happens after you contact us
- We reply within one business dayWe respond to your enquiry and identify any context needed for the discussion.
- A call about which module is in the wayWe discuss your product goals, the existing components and the systems that depend on them.
- A written modernization roadmapFor an agreed assessment, we document the recommended approach, phases, risks and estimate against the system we review.
- Contracts and NDAs, then a start dateSigned before anyone gets access to your repository. Most engagements start within two to four weeks.
09Delivery
How does software modernization work?
Software modernization starts with assessment and design, followed by implementation, cutover and handover. For a feasible incremental approach, we work module by module. Your technical and domain owners provide access, confirm required behavior and data rules, and approve releases.
- Audit and roadmapWe inspect the code, data model and integrations against the product roadmap. We assess what to retain and whether refactoring, re-platforming, phased rebuilding or replacement fits the requirements.You getA written modernization roadmap with the proposed approach, phases, target stack, risks and estimate.
- Design the target and the seamWe design the target architecture and, for a phased transition, the interface between old and new. Data ownership, exchanges and reconciliation criteria are defined with your system and data owners.You getA target architecture, the interface contract between old and new, and the data reconciliation plan.
- Rebuild module by moduleWe implement the component, migrate the data in scope and test behavior and connected workflows against the acceptance criteria. We have ISTQB-certified QA engineers; testing responsibilities and coverage are defined for the engagement.You getAn implemented component with test results and the migration and reconciliation records in scope.
- Cut over and retire the legacy pathWe check the component against release and data reconciliation criteria, then carry out the agreed transition. Retiring the legacy path depends on the connected systems and workflows that still use it.You getThe agreed cutover, records of any retired legacy path, and the monitoring included in scope.
- Harden and hand overWe verify the remediation in scope, document the interfaces and transfer the agreed operating knowledge. For a planned AI readiness initiative, clean data and documented APIs are assessed alongside access, security and the intended use.You getDocumented APIs, remediation results and remaining findings, plus the agreed handover and support plan.
10Client voices
Client perspectives on the engineering
Our platform has been refactored to Laravel ensuring the code base is more stable, easier to maintain and easier to add new features. Their professionalism and quality of work have stood out in the partnership. We have had the code audited by a 3rd party who was extremely complimentary of the work.
Our website’s overall functionality has been improved both in frontend possibilities and user experience as well as backend aspects of website management and financial monitoring. These are not easily qualitfiable but there has been a net gain in available staff hours for alternative projects as a result of improved website abilities reducing workload.
Site was migrated and re-written, the new system is much more stable, and performance highly improved. Excellent technological level. highly responsive and communicative. They are highly committed to the project and business goals.
We’ve seen enhanced customer satisfaction thanks to unicrew’s work. Our customers love the UI and speed of the application. We’ve received positive feedback, and there are no errors in the system. unicrew meets their deadlines and stays on budget.
The goal was to replace legacy UI elements with new UI components. The new UI components already existed, key challenge was to map the existing implementations to the new ones while not losing functionality. They were super responsive and did exactly as we agreed upon. The colleague they send to us was an extremely good fit to the problem that we have described.
11Case studies
Application modernization and platform evolution
For Triathlon Ireland, we rewrote the main functionality from WebForms to .NET Core 3.1 plus a Vue JS module, module by module, and updated the design and user experience. unicrew has built software since 2012; older client reviews name our former Artelogic brand.
See all case studies
LeisureSaaS modernization for a paddle sports center in CaliforniaA kayaking and paddleboard rental business in the Santa Barbara area wanted one system for equipment, customers, time and billing. That system is Adventure Rental System.15-20%Increase in revenue
HospitalityAdaptable booking platform for entertainment venuesunicrew developed a platform for Booked It that enhanced the customer experience for nightclub, entertainment center, and festival goers.600+Businesses using the platform- SaaSAWS costs down 30%+ for a US B2B SaaS platformunicrew became the programming team for a B2B SaaS platform that had run for over a decade, streamlined how it used AWS and Heroku, and sped up rollouts.30%+Lower AWS costs
12Questions
About legacy software modernization with unicrew
The scope of legacy software modernization depends on what the application must support next and how it connects to the business. Assessment turns those requirements into an implementation decision.
Legacy application modernization can improve maintainability, update unsupported dependencies and make the application easier to extend. We define the intended benefits against your product and operating requirements.
- Refactoring and re-engineering address the code and architecture involved in planned changes.
- Security remediation addresses prioritized findings in dependencies, encryption and access control.
- Data and interface work supports new integrations and reporting. Clean data and documented APIs can also support an AI initiative, subject to its access, security and evaluation requirements.
The price follows the assessed scope: application changes, data migration, integrations, testing and cutover work. The assessment establishes the approach and dependencies needed for an estimate.
The model should fit how clearly the work can be specified and how you want to direct delivery:
- Time and materials: billed hourly, quoted per project.
- Fixed price: outcome based, quoted per project.
- Team extension: billed monthly per team member.
We estimate the implementation schedule after assessing the application and defining the changes. A module's size alone does not capture the data, integration and release work it needs.
The plan accounts for dependencies, available tests, migration and reconciliation, and the operational windows in which changes can be released. A feasible modular approach lets us plan acceptance and cutover by component; a complete replacement needs a plan for the whole transition.
We scope the integrations that the modernized system must preserve or update, then validate the connected workflows. Compatibility depends on the interfaces and access supported by each tool.
We map ERP, CRM, payment and operational dependencies during assessment, including data contracts and ownership. A client-led re-platforming off WordPress connected Shopify storefronts to Microsoft Dynamics through custom middleware, alongside product information and sales-channel work.
We plan the transition around the services that must remain available, the shared data and the release windows your operations can support. Where component boundaries and interfaces allow it, rebuilding module by module can let old and new parts coexist.
That approach depends on being able to route requests and manage data between the systems. Assessment identifies those constraints; the cutover plan defines validation and readiness criteria with your technical and operational owners. If the transition requires a service interruption, it needs an agreed operational window.
You may be able to add AI through the existing application's APIs. Modernization becomes relevant when the intended use needs changes to data quality, interfaces or access controls.
Our AI readiness assessment examines the use case, available data, documented APIs, security and evaluation requirements. It can identify a focused application change or an integration on the existing system, depending on what that assessment finds.
Modernization is worth assessing when the application's current design or support status affects planned product changes, integrations or operating requirements. It can also prepare for future needs before they become urgent.
We weigh the value of retaining your business logic against technical debt, migration work and the cost of continued upkeep. Software maintenance and support fits an application that meets its intended needs; a re-host addresses infrastructure. Replacement or a packaged product may fit when its functionality and integration requirements can be met more directly.
Compare how each partner connects the proposed changes to your application, business requirements and delivery responsibilities. Relevant engineering experience should support a specific plan.
- Ask how they choose between retention, refactoring, re-platforming and replacement, and request relevant examples within confidentiality limits.
- Check the proposed interfaces, data reconciliation, testing and cutover criteria, including conditions that make phased coexistence feasible.
- Agree who sets priorities, approves behavior and releases, owns the deliverables, and handles transfer and support.
unicrew holds ISO 27001:2022 and ISO 9001:2015 certifications, renewed through a multi-stage audit with Quay Audit UK.