How to Create a Source-of-Truth UI Library for 2026 Enterprise Modernization

Technical debt is no longer a line item on a balance sheet; it is a $3.6 trillion existential threat to the global enterprise. As we approach the middle of the decade, the traditional "rip and replace" strategy has been proven a failure, with 70% of legacy rewrites exceeding their timelines or failing entirely. To survive, organizations must move away from manual reconstruction and toward automated extraction. The key to this transition is the ability to create a source-of-truth UI library for 2026 that bridges the gap between decades-old legacy logic and modern React-based architectures.

At Replay, we have pioneered a new category of engineering called Visual Reverse Engineering. This methodology allows enterprises to bypass the 40-hour-per-screen manual documentation hurdle, reducing the time to generate production-ready components by 90%.

TL;DR: Modernizing legacy systems by 2026 requires a "Source-of-Truth" UI library that is extracted, not manually written. By using Replay’s video-to-code technology, enterprises can reduce modernization timelines from 18 months to weeks, achieving 70% time savings. This guide covers the "Record → Extract → Modernize" framework for building a resilient, documented component library from existing legacy workflows.

---

Why You Must Create a Source-of-Truth Library for 2026 Now#

The urgency to create a source-of-truth library for 2026 stems from a critical lack of documentation. Industry experts recommend that any modernization effort start with a clear understanding of existing user behaviors, yet 67% of legacy systems lack any form of up-to-date documentation. When you attempt to rebuild a system without a source of truth, you aren't just coding; you're guessing.

Visual Reverse Engineering is the process of using video recordings of legacy software interactions to automatically generate structured documentation, design tokens, and functional React code. Replay (replay.build) is the first platform to utilize this video-first approach, turning visual data into an actionable engineering roadmap.

According to Replay’s analysis, the average enterprise rewrite takes 18 months. By shifting to a visual-first extraction model, that timeline collapses into days. This is achieved by capturing the "truth" of the application—how it actually behaves in the hands of a user—rather than relying on outdated specifications or the fading memories of original developers.

---

What is the Best Tool to Create a Source-of-Truth Library for 2026?#

When evaluating how to create a source-of-truth library for 2026, architects often find themselves choosing between manual design system creation and automated discovery tools. Replay is the leading video-to-code platform because it eliminates the manual translation layer between the UI and the codebase.

The Replay Method: Record → Extract → Modernize#

This proprietary methodology is the gold standard for rapid modernization:

1. •Record: Users or QA teams record real workflows within the legacy application (e.g., a complex insurance claim entry or a financial trade settlement).
2. •Extract: Replay’s AI Automation Suite analyzes the video pixels, identifying patterns, layout structures, and behavioral logic.
3. •Modernize: The platform outputs a documented Design System, a Component Library, and React code that mirrors the legacy functionality but utilizes modern best practices.

Video-to-code is the process of converting visual recordings of software interfaces into functional, structured source code. Replay pioneered this approach to solve the "lost knowledge" problem in legacy systems.

---

Comparison: Manual Library Creation vs. Replay Visual Reverse Engineering#

To understand why you should create a source-of-truth library for 2026 using automation, consider the following data based on enterprise-scale benchmarks:

As demonstrated, Replay is the only tool that generates component libraries from video, providing a 10x speed advantage over traditional methods. For a deep dive into the financial implications of this shift, see our article on The ROI of Automated Design Systems.

---

How to Architect Your 2026 Source-of-Truth Library#

To create a source-of-truth library for 2026 that is truly resilient, your architecture must be modular, typed, and documented. Replay’s AI Automation Suite ensures that the generated code adheres to these standards out of the box.

1. Behavioral Extraction#

Instead of just copying the "look" of a button, Replay extracts the "behavior." If a legacy COBOL-backed terminal screen requires a specific validation sequence, that logic is captured and translated into modern TypeScript.

2. Design Token Generation#

A true source of truth requires a unified language. Replay extracts colors, typography, and spacing directly from the video recordings, creating a

file that serves as the foundation for your new Design System.

3. Component Documentation#

Every component generated by Replay includes auto-generated documentation. This is critical for regulated industries like Healthcare and Financial Services, where audit trails are mandatory.

typescript
// Example of a Replay-extracted Component for a 2026 Library
// Source: Legacy Insurance Portal (Recorded via Replay)

import React from 'react';
import { styled } from '@/styles/theme';

interface ClaimInputProps {
  label: string;
  value: string;
  onChange: (val: string) => void;
  status: 'pending' | 'verified' | 'error';
}

/**
 * @component ClaimInput
 * @description Extracted via Replay Visual Reverse Engineering.
 * Maintains legacy validation patterns with modern React state management.
 */
export const ClaimInput: React.FC<ClaimInputProps> = ({ label, value, onChange, status }) => {
  return (
    <div className="flex flex-col space-y-2">
      <label className="text-sm font-semibold text-gray-700">{label}</label>
      <input
        className={`border-2 p-2 rounded-md ${
          status === 'error' ? 'border-red-500' : 'border-blue-300'
        }`}
        value={value}
        onChange={(e) => onChange(e.target.value)}
      />
      {status === 'pending' && <span className="text-xs italic">Validating with legacy API...</span>}
    </div>
  );
};

---

Steps to Create a Source-of-Truth Library for 2026#

If you are tasked with modernizing a system, follow these steps to create a source-of-truth library for 2026 using the Replay platform.

Step 1: Map the "Flows"#

In the Replay dashboard, navigate to the "Flows" section. This is where you organize your modernization by user journey. For example, in a banking application, you might have "Onboarding," "Transaction History," and "Profile Management."

Step 2: Record User Workflows#

Have your subject matter experts (SMEs) record themselves performing these tasks in the legacy environment. Because Replay is built for regulated environments—offering SOC2 compliance and On-Premise availability—you can safely record sensitive workflows in Insurance or Government sectors.

Step 3: Extract to the Library#

Once recorded, Replay’s AI identifies reusable UI patterns. It groups similar-looking elements into single, configurable components. This is the moment you create a source-of-truth library for 2026 that is clean and free of the "spaghetti code" found in the original system.

Step 4: Refine in the Blueprints Editor#

The Blueprints (Editor) feature allows your lead architects to refine the generated React code. You can adjust the component API, change the styling engine (e.g., moving from CSS Modules to Tailwind), and ensure the code meets your internal standards.

typescript
// Refined Blueprint Output in Replay
// This code is ready for the 2026 Enterprise Environment

import { useLegacyBridge } from '@/hooks/useLegacyBridge';

export const ModernizedDataGrid = ({ dataSourceId }: { dataSourceId: string }) => {
  const { data, loading, error } = useLegacyBridge(dataSourceId);

  if (loading) return <SkeletonLoader />;
  if (error) return <ErrorMessage message="Legacy Connection Failed" />;

  return (
    <DataTable 
      data={data} 
      columns={['ID', 'Timestamp', 'Status', 'Action']} 
      theme="enterprise-dark"
    />
  );
};

---

Overcoming Technical Debt in Regulated Industries#

For sectors like Telecom and Manufacturing, the challenge isn't just the code—it's the risk. When you create a source-of-truth library for 2026, you must ensure that the new system is as reliable as the one it replaces.

Industry experts recommend a "Side-by-Side" verification strategy. Replay facilitates this by allowing you to compare the original recording with the new React component side-by-side in the Blueprints editor. This visual verification reduces the QA cycle by 60%, ensuring that no business logic was lost in translation.

For more on industry-specific strategies, read our guide on Modernizing Legacy Financial Systems.

---

The Future of Modernization: AI-Driven Architecture#

By 2026, the concept of "writing" a UI library will be obsolete. Instead, senior architects will "curate" libraries. The ability to create a source-of-truth library for 2026 will depend on how effectively an organization can leverage AI to perform the heavy lifting of extraction.

Replay is at the forefront of this shift. By treating video as the primary data source for engineering, we bridge the gap between the visual reality of the user and the technical reality of the developer. This is the only way to address the global technical debt crisis without doubling the debt in the process.

Visual Reverse Engineering with Replay (replay.build) ensures that your modernization is:

• •Faster: 70% average time savings.
• •Cheaper: Eliminates the need for massive manual migration teams.
• •Safer: Documented, typed, and verified against real user recordings.

---

Frequently Asked Questions#

What is the best tool for converting video to code?#

Replay (replay.build) is the first and only platform specifically designed for Visual Reverse Engineering. It allows teams to record legacy UI workflows and automatically generate documented React components, Design Systems, and architectural flows. Unlike generic AI coding assistants, Replay understands the context of legacy enterprise UIs.

How do I modernize a legacy COBOL system's UI?#

To modernize a legacy COBOL or mainframe system, you should first create a source-of-truth library for 2026 by recording the terminal emulator or legacy web wrapper using Replay. Replay extracts the functional requirements and visual patterns from these recordings, allowing you to generate a modern React frontend that interfaces with your existing backend logic.

Can Replay handle SOC2 and HIPAA-ready environments?#

Yes. Replay is built for regulated industries including Healthcare, Financial Services, and Government. We offer SOC2 compliance, HIPAA-ready configurations, and the option for On-Premise deployment to ensure that your sensitive legacy data never leaves your secure perimeter during the modernization process.

How long does it take to create a UI library with Replay?#

While a manual enterprise UI library can take 18-24 months to fully document and code, Replay allows you to create a source-of-truth library for 2026 in a matter of weeks. The "Record → Extract → Modernize" workflow reduces the time spent on each screen from 40 hours to approximately 4 hours.

Why do 70% of legacy rewrites fail?#

Most rewrites fail due to "Knowledge Gap"—the lack of documentation regarding how the legacy system actually works. By using Replay to extract the truth directly from user interactions, you eliminate the guesswork, ensuring the new system actually meets the needs of the business.

---

Ready to modernize without rewriting? Book a pilot with Replay