In a fast-paced tech landscape

Sticking with outdated tools can hold you back. Over time, performance degrades, legacy code becomes increasingly difficult to maintain, and the user interface feels stale and outdated. This was the situation our team faced with a 10-year-old application built on an early version of a legacy framework.

The Challenge

Our app was still running on a legacy frontend architecture that couldn’t meet modern demands—such as responsive design, dynamic component loading, and accessible user experiences. We knew we had to modernize, but a complete rewrite wasn’t immediately feasible.

Why Not Just Upgrade the Legacy Stack?

Upgrading to the latest version of the existing stack would have required a full refactor to adopt an asynchronous architecture, with significant changes to our codebase and workflow. After a thorough evaluation, we determined that continuing with the same toolset would limit our ability to scale, modernize the UI, and integrate with today’s development tools.

Why We Chose ReactJS

We evaluated several popular front-end frameworks—Vue.js, Angular, Svelte—but ReactJS stood out for multiple reasons:

• Rich ecosystem: backed by a vast collection of libraries (React Router, Redux, etc.)

• Performance: React’s Virtual DOM ensures fast, efficient updates.

• Component-based architecture: ideal for gradual migration and reuse.

• Massive community: abundant tutorials, documentation, and support.

• Interop flexibility: easy to embed React components into legacy environments.

Our Incremental Migration Strategy

Rather than rewriting the entire application at once, we adopted a step-by-step hybrid approach:

• Build new pages using ReactJS, embedding them within the existing application structure.
• Create reusable React components, styled using the IBM Carbon Design System to maintain visual consistency.
• Migrate older sections of the application one-by-one to React, while maintaining backward compatibility.
• Implement conditional routing to support seamless transitions between legacy and new modules.

Results

This progressive strategy delivered multiple wins:

• Improved performance across the board (faster load times, smoother interactions).
• Modern, responsive UI aligned with IBM Carbon design standards.
• Faster development cycles, thanks to modular React components.
• Upskilled our dev team, future-proofing them with React expertise.

Final Thoughts

ReactJS proved to be a powerful bridge between legacy code and modern web architecture. Its flexibility enabled us to modernize our application without a complete rebuild or disrupting our users. For teams dealing with aging front-end stacks, ReactJS offers a practical and scalable path forward—whether you’re starting from scratch or modernizing gradually, one component at a time.