Case studies

Modernization grounded in real application work.

These projects reflect the experience and capabilities of our team.

Prior Team Experience • Global manufacturer

Modernizing a mature Rails application, module by module.

Global manufacturer
Business-critical application
Module-by-module modernization

Illustrative comparison: on the left, a server-rendered Rails application screen showing a fictional production order; on the right, the same order in a modern React module. Beneath them, the legacy Rails views connect directly to the existing Rails business logic, while the React module connects through a Rails REST API. Both use the same retained business logic.

The situation

Members of the LeMod team worked with a global manufacturing company on a mature Rails application with server-rendered views. The application held business logic the company relied on.

The challenge

The interface needed to change, but the business logic was proven and valuable. Replacing it all at once would have put that logic at risk.

The approach

The existing Rails business logic was kept. Rails REST APIs exposed what the application already did. React replaced the server-rendered screens one module at a time.

What this shows

The interface can be modernized without a wholesale replacement of the business logic behind it.

Preserve what already works

Keep proven Rails business logic and replace the layer that creates the constraint.

Avoid the big-bang rewrite

Old and new screens operate side by side while modules are rebuilt.

Modernize module by module

Each module moves to React on top of Rails REST APIs.

Prior Team Experience • Travel operations

From an AS/400 back-office system to a modern application platform.

Business-critical operations
Incremental transformation

Illustrative comparison: on the left, a green-on-black AS/400-style travel booking maintenance screen with fixed-width fields and function-key commands; on the right, the same fictional booking in a modern web application with navigation, booking details, status, segments and passengers.

The starting point

A travel company ran its back-office operations on an IBM AS/400 application. The modernization team worked side-by-side with in-house experts to reconstruct the business logic from screens, fields and workflows—without access to source code.

Build the first web-based replacement

Core back-office operations moved from the AS/400 environment to a new web-based application, which continued to evolve for years.

The current transformation

As parts of that foundation reached end-of-life, the application is being rearchitected around a modern React frontend and REST API layer—incrementally, AI-assisted and human-controlled—while hardening the engineering foundation and redesigning the user experience.

Modernization can begin without source code

Behavior reconstructed through screen analysis, workflow mapping and domain experts.

Institutional knowledge is an asset

Hidden operating knowledge became explicit workflows, rules and data structures.

Make change safer

Clearer boundaries, APIs, reusable components and stronger testing.

Your application may not need a rewrite.

Find out where modernization can create the most value with the least unnecessary risk.

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