What are application modernization services?

Application modernization services update legacy software to modern technology, architecture and infrastructure without losing the business logic it holds. Typical work includes a modernization assessment, rehosting or replatforming to the cloud, re-architecting monoliths into services, upgrading outdated frameworks, redesigning the UI and UX, exposing functionality through APIs and migrating data to modern databases. The goal is software that is cheaper to run, easier to change, more secure and ready for integrations, analytics and AI, while users keep working without disruption during the transition.

How much does legacy application modernization cost?

Legacy application modernization cost depends on size, complexity and the chosen strategy. A modernization assessment usually costs $5,000 to $15,000 and takes two to four weeks. Modernizing a single business application typically ranges from $40,000 to $150,000, while large multi-system programs with heavy data migration cost more. The main cost drivers are lines of code and modules, the number of integrations, data volume and quality, compliance needs such as HIPAA or SOC 2, and whether you rehost, refactor or rebuild. Phased delivery spreads the investment and shows value early.

How long does application modernization take?

Smaller applications can usually be modernized in 3 to 6 months. Large, complex enterprise systems typically take 9 to 18 months, delivered in phases so value arrives throughout rather than at the end. Timelines depend on code size, the number of integrations, data migration effort, test coverage of the existing system and how quickly stakeholders can review and approve releases. A short assessment at the start gives you a realistic schedule per module, and the strangler approach means the first modernized features often reach users within the first two to three months.

Should we rewrite our legacy application from scratch?

Usually not all at once. Big-bang rewrites carry high risk because years of business rules live inside the old code, and projects often run over budget before delivering anything. We typically recommend incremental legacy application modernization with the strangler pattern, replacing modules one at a time while the old system keeps running. A rewrite makes sense only for parts where the code is unmaintainable, the technology is unsupported or the business process itself is changing. The assessment phase tells you which modules to refactor, replatform or rebuild.

What legacy technologies do you modernize?

We modernize a wide range of legacy technologies, including VB6, classic ASP, older .NET Framework, legacy PHP, old Java and Struts, AngularJS, Delphi, PowerBuilder-style desktop apps, Microsoft Access and on-premise SQL Server or Oracle systems. We move them to .NET, Java Spring Boot, Node.js, Python, React and Angular, running on AWS, Azure or Google Cloud with managed databases. Where a mainframe or packaged system must stay, we wrap it with APIs so new applications can use its data and functions safely.

Will modernization disrupt our operations?

Modernization should not disrupt daily operations when it is done incrementally. Our approach keeps the legacy system running while new parts are introduced gradually, using parallel runs, feature flags, blue-green deployments and tested rollback plans. Cutovers are scheduled for low-traffic windows, and data is reconciled before each switch. Users get training and short guides for new screens, and support staff are briefed ahead of every release, so disruption stays minimal and any issue can be reversed within minutes rather than days.

Why choose Webshark for application modernization?

Webshark has delivered 580+ projects for 280+ active clients across 18+ countries since 2019, working under ISO 27001 and CMMI Level 3 certified processes. For application modernization services that matters, because legacy work demands disciplined discovery, testing and change control. Our teams cover architecture, development, QA, cloud, DevOps and UX in one place, so you do not juggle several vendors. We overlap with US business hours, share progress in every sprint and plan modernization in phases tied to measurable business outcomes.

Can you add AI to our modernized application?

Yes. Once a legacy application is modernized with clean APIs and well-structured data, adding AI becomes practical. Common additions include AI assistants inside the app, document and invoice processing, smart search, forecasting and anomaly detection, using models from OpenAI, Anthropic, Google or open-source options hosted in your own cloud. We design these features with access controls, audit logs and data privacy in mind, especially for healthcare and financial data. To explore options, see our AI integration services.

Which technologies do you use?

For modernization projects we use React, Next.js and Angular on the front end; Node.js, Python, Java Spring Boot and .NET on the back end; and Flutter or React Native when mobile apps are part of the scope. Infrastructure runs on AWS, Azure or Google Cloud with Docker, Kubernetes, Terraform and managed databases such as PostgreSQL and SQL Server. We choose the target stack based on your goals, budget, existing licenses and in-house skills, so your team can maintain the modernized application confidently.

Who owns the source code and IP?

You do. All source code, designs, documentation, test suites, data migration scripts and infrastructure-as-code from your application modernization project belong to you, and the contract assigns full IP ownership on payment. We sign NDAs before discovery starts, work in repositories you control or transfer to you, and never reuse your proprietary business logic elsewhere. Because legacy systems often hold sensitive data, access is limited to named team members under our ISO 27001 controls and removed when the engagement ends.

Can I hire a dedicated team instead of a fixed-price project?

Yes. Many clients prefer a dedicated team for long modernization programs where scope evolves as legacy modules are uncovered. You can hire dedicated engineers, from one developer to a full squad with an architect, project manager and QA, on flexible monthly contracts. The team works in your tools and sprint rhythm, with overlap in US business hours, and can scale up during heavy migration phases and down once the system stabilizes. See our hire full-stack developers page.

Do you provide support after launch?

Yes. After your modernized application goes live, our support plans cover application and infrastructure monitoring, bug fixes, security patches, dependency and framework upgrades, performance tuning and new feature development. Plans come with agreed response times based on severity, monthly reports and a named team that already knows your code and history. Support overlaps with US business hours, and we schedule regular upgrade cycles so the platform stays current and does not slide back into legacy status within a few years.

TRUSTED BY ENTERPRISES AND GROWING BUSINESSES IN 18+ COUNTRIES

Turn ageing, costly legacy systems into fast, secure, cloud-ready software, one safe step at a time

Legacy Application Modernization Services

Legacy code and architecture assessment with a risk-ranked modernization roadmap.
Re-platform, re-architect or rebuild, chosen module by module.
Strangler-pattern migrations that keep the business running throughout.
Modern UX, APIs, cloud hosting and automated testing on the new platform.

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Application Modernization Services Without Business Disruption

Webshark provides application modernization services for organisations running business-critical software on old frameworks, unsupported languages, monoliths or on-premise servers. Legacy applications slow down change, cost more to maintain and create security risk, but a big-bang rewrite is risky too. Our legacy application modernization approach assesses your system, ranks modules by business value and risk, and modernizes step by step using the strangler pattern, so old and new run side by side until each part is safely replaced. We move apps to modern stacks such as .NET, Java Spring Boot, Node.js and React, re-architect them into services, add APIs and move them to the cloud. Moving infrastructure first? See our cloud migration services.

Years of Software Engineering Experience

580+

Projects Delivered Across Industries

18+

Countries Served, Including the USA

280+

Active Clients Trusting Our Engineering

Application Modernization Services Built Around Security and Compliance

Every application modernization engagement follows ISO 27001 certified security and CMMI Level 3 delivery processes, with data handling aligned to GDPR, CCPA, HIPAA and the industry standards your auditors expect.

GDPR

CCPA

HIPAA

DPDP Act, 2023

PCI DSS

PSD2

EMV & 3DS

ISO/IEC 9001

ISO/IEC 27018

SOC 2 Type II

FISMA

NIST Cybersecurity Framework

ISO 13485

PIPEDA

ISO/IEC 27001

OWASP

W3C

Application Modernization Services We Offer

From a code audit to a complete platform rebuild, our application modernization services cover every step of moving from legacy to modern.

Legacy Application Modernization Strategies

We choose the right path for each part of your system, balancing cost, speed, risk and long-term value.

Legacy Assessment and Roadmap

Code, architecture, dependency and security review with a prioritised modernization plan.

Re-Platforming

Moving apps to modern runtimes, managed databases and cloud hosting with minimal code change.

Re-Architecting to Microservices

Breaking monoliths into services with clear APIs, independent deployment and scaling.

Technology Stack Upgrades

Migrating from VB6, classic ASP, old .NET, legacy PHP, Java or AngularJS to modern frameworks.

UI/UX Modernization

Redesigning outdated interfaces into fast, responsive, accessible web and mobile experiences.

API Enablement and Integration

Exposing legacy data and functions through secure APIs for apps, partners and AI.

Why Choose Our Application Modernization Company

Modernization succeeds when risk is managed carefully. Our approach protects your operations at every step.

Incremental Delivery With Low Risk

We avoid risky big-bang rewrites. Using the strangler pattern, feature flags and parallel runs, we replace one capability at a time while the legacy system keeps serving users. Each phase delivers working software and measurable value, and rollback plans protect operations if anything needs adjusting.

Knowledge Recovery From Old Systems

Legacy systems often hold years of undocumented business rules. We analyse code, databases and logs, interview long-time users and document every rule before rebuilding it. Automated tests capture current behaviour, so the modern application does exactly what the business needs, without losing critical logic.

How Our Legacy Application Modernization Works

A proven, phased process takes your application from legacy to modern while keeping the business running.

Assess the Current System

Every legacy application modernization engagement starts with a hands-on audit. We review source code, architecture, infrastructure, integrations, data quality and security posture, then measure maintenance costs, outage history and user pain points. Static analysis tools and stakeholder interviews expose technical debt and hidden dependencies. Within two to four weeks you receive an assessment report that scores each module and recommends a strategy for it: retain, rehost, replatform, refactor or replace.

Define the Target Architecture

Next we design the target architecture for your modernized application, usually cloud-native with services, APIs and managed databases, and pick a stack your in-house team can maintain. The modernization roadmap sequences modules by business value and risk, with milestones, budgets and success metrics agreed upfront. You get architecture diagrams, a technology decision record and a phased plan, so leadership can approve funding with a clear view of cost, timing and expected payback.

Build a Safety Net of Tests

Before we change a single line, we wrap the critical behavior of the legacy system in automated tests. Characterization tests capture how calculations, workflows, reports and integrations really behave today, including the quirks users rely on. This safety net confirms the modern version follows the same business rules and catches regressions on every release. You receive a reusable test suite and coverage report that keeps protecting quality long after the project ends.

Modernize Module by Module

Using the strangler fig pattern, new services and screens replace legacy parts one at a time, with traffic routed through APIs or a gateway. Each increment runs in two to six week sprints and ships to production behind feature flags, so users move to new features gradually. You see working software early and often, risk stays contained to one module at a time, and the legacy system shrinks steadily until it can be safely retired.

Migrate Data Safely

Data is often the riskiest part of modernization, so we treat it as its own workstream. We map old schemas to new ones, cleanse duplicates and bad records, and write repeatable migration scripts. Parallel runs and automated reconciliation compare record counts, balances and key fields before every cutover. Historical data stays accessible for reporting and audits, integrations keep working throughout, and you get signed-off validation reports for each migration wave.

Modern DevOps and Cloud

The modernized application runs on AWS, Azure or Google Cloud with CI/CD pipelines, infrastructure as code, centralized logging, monitoring and autoscaling. Releases that once took weeks of manual effort become routine, low-risk deployments that can happen several times a week. You receive documented pipelines, Terraform or equivalent scripts and dashboards, plus right-sized infrastructure that typically lowers hosting and maintenance costs compared with the old on-premise setup.

Support and Continuous Improvement

After go-live we monitor performance, error rates and user feedback, fix issues quickly and keep improving the platform in planned releases. We run knowledge transfer sessions, hand over architecture and runbook documentation, and can pair with your developers until they are comfortable owning the code. Ongoing support plans cover security patches, dependency upgrades and new features, so your modernized application never drifts back into becoming the next legacy system.