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Modernizing a Critical Legacy Application Without Business Disruption

How an insurance services provider moved from GWT and tightly coupled Java services to Angular, Spring Boot REST APIs, and an optimized data-access layer.

Project Type

Enterprise Application Modernization

Industry

Insurance

Tech Stack
Angular Spring Boot REST API MySQL

About the Client

The client is a leading US-based insurance technology provider operating a business-critical application that supports core workflows and internal system integrations.

Business Requirement

The client needed to modernize its application without interrupting active operations. The work also needed to improve usability, performance, maintainability, and security while preparing the application for future integrations.

The modernization program needed to:

Replace the outdated GWT frontend with a modern, maintainable user experience.

Decouple backend functionality from legacy Java services and improve scalability.

Optimize application and database operations across high-volume transactions.

Remove vulnerable third-party dependencies and strengthen API authentication.

Preserve data continuity across internal systems during a controlled migration.

0

Critical business disruptions during migration cutover activities

100%

Commercial UI control dependencies eliminated

3

Core architecture layers modernized across the UI, services, and data access

Our Solution

Vee Technologies delivered an incremental modernization program centered on Angular, Spring Boot REST services, and Spring JDBC. The work covered frontend redesign, backend re-architecture, SQL optimization, dependency rationalization, API security, workflow improvements, testing, and production stabilization.

Incremental modernization solution illustration

Challenges and Solutions

1

Legacy Frontend Constraints

The GWT frontend limited responsiveness, usability, and ongoing enhancement. The interface was rebuilt in Angular with reusable components and more intuitive navigation.

2

Backend Coupling and Dependencies

Legacy Java services and dependencies on internal systems increased the risk of change. Spring Boot REST services introduced clearer boundaries, while dependency mapping helped protect continuity.

3

Performance and Data Access

Existing service and database operations created processing delays. SQL was reviewed and optimized for Spring JDBC to improve data access and transaction handling.

4

Security and Continuity Risk

A vulnerable third-party component had to be removed without breaking existing functionality. Native alternatives, stronger API controls, authentication improvements, and staged testing helped manage security and deployment risk.

Our Approach

The team first mapped business functions, application behavior, data interactions, technical dependencies, and integration points. Modernization then progressed through controlled Agile sprints with stakeholder feedback and ongoing validation.

Assessment and Knowledge Transfer

Application modules, business rules, database interactions, internal integrations, and undocumented dependencies were reviewed to define the migration scope and identify high-risk areas.

Target Architecture and Modular Migration

An architecture based on Angular and Spring Boot established clearer service boundaries, REST APIs, security controls, and an incremental migration sequence. Modules were migrated progressively to reduce change risk.

Data Access and Performance Optimization

Existing SQL queries were evaluated for compatibility with Spring JDBC and the redesigned backend. Targeted modifications supported faster execution, lower latency, and continued compatibility.

Security and Dependency Remediation

Outdated and vulnerable third-party components were identified and replaced with equivalent native libraries. API protection and authentication were also strengthened.

Agile Validation, Deployment, and Stabilization

Incremental sprints supported development, stakeholder feedback, testing, and early risk identification. Dedicated resources helped resolve issues and prepare for deployment.

Results

The migration cutover was completed without critical business disruptions. The new Angular application eliminated commercial UI control dependencies by replacing the paid Handsontable component with a custom table built using standard HTML controls.

The frontend was developed without commercial third-party UI controls, reducing licensing costs and vendor dependency. Since January 2026, the client has onboarded a new end-client and completed 136 configuration and support tickets. Making changes in the legacy application had been more challenging because of its outdated technology stack.

0

Critical Business Disruptions

Migration cutover activities were completed without critical business disruption.

100%

Commercial UI Control Dependencies Eliminated

The paid Handsontable component was replaced with a custom Angular table built using standard HTML controls.

100%

Open-Source Frontend Technology Adoption

The Angular application was developed without commercial third-party UI controls, reducing licensing costs and vendor dependency.

136

Configuration and Support Tickets Completed

Completed alongside the onboarding of a new end-client.

Ready to Modernize Your Legacy Applications?

Modernize critical enterprise applications while maintaining operational continuity. Vee Technologies brings together assessment, architecture redesign, frontend and backend modernization, API engineering, security remediation, data optimization, and controlled migration to build secure, scalable platforms.

Discuss Your Application Modernization Requirements
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