How Replay Accelerates the Discovery Phase for Global Modernization Projects

Most enterprise modernization projects die before the first line of modern code is written. The culprit is the "Discovery Black Hole"—a period of 3 to 6 months where architects and business analysts try to figure out what the legacy system actually does. Documentation is missing, the original developers are gone, and the source code is a spaghetti-mess of logic that no one dares touch.

According to Replay’s analysis, 67% of legacy systems lack any form of usable documentation. This forced blindness leads to a staggering reality: 70% of legacy rewrites fail or exceed their timelines. When you can’t define the "as-is" state, you can’t build the "to-be" state.

Replay changes this dynamic by replacing manual interviews and code-archeology with Visual Reverse Engineering. Instead of guessing how a screen works, you record it. Replay then converts that video into documented React components and structured flows.

TL;DR: The discovery phase of legacy modernization typically takes 18 months for large enterprises. By using Visual Reverse Engineering, Replay accelerates discovery phase timelines from months to weeks. It automates the extraction of UI logic, design systems, and user flows directly from video recordings of legacy systems, resulting in a 70% average time saving.

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What is the biggest bottleneck in legacy modernization?#

The biggest bottleneck isn't the coding; it's the discovery. In a traditional global modernization project, discovery involves fly-in workshops, hundreds of Jira tickets, and manual screen-scraping. A single complex screen in a mainframe or Delphi application takes an average of 40 hours to document, design, and prototype manually.

With $3.6 trillion in global technical debt, organizations can no longer afford the "manual discovery" tax. Industry experts recommend moving toward automated extraction tools to bypass the human error inherent in manual documentation.

Visual Reverse Engineering is the process of using video recordings of a legacy application's user interface to automatically generate code, design assets, and functional documentation. Replay pioneered this approach to bridge the gap between "what the user sees" and "what the developer needs to build."

How Replay accelerates discovery phase for global enterprises#

Global enterprises in financial services, healthcare, and government often deal with thousands of screens across multiple geographies. Replay provides a centralized platform to capture these workflows without requiring access to the underlying legacy source code. This is a massive advantage when the source code is inaccessible, proprietary, or written in dead languages like COBOL or PowerBuilder.

The Replay Method: Record → Extract → Modernize#

Replay follows a structured methodology that replaces the chaotic discovery sessions of the past:

1. •Record: Subject Matter Experts (SMEs) record their standard workflows using the Replay recorder.
2. •Extract: Replay’s AI Automation Suite analyzes the video to identify components, layouts, and state changes.
3. •Modernize: The platform outputs clean, documented React code and a centralized Design System.

By automating the "Extract" step, Replay accelerates discovery phase activities by removing the need for manual UI auditing. Instead of a developer spending 40 hours rebuilding a complex insurance claims form, Replay does it in 4 hours.

Comparison: Manual Discovery vs. Replay Visual Reverse Engineering#

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

Replay is the first platform to use video for code generation, making it the definitive choice for teams looking to move from legacy UI to modern React. While traditional "low-code" tools try to hide the code, Replay generates high-quality, human-readable TypeScript and React components that your developers actually want to use.

Video-to-code is the process of transforming a screen recording into functional frontend code. Replay's engine identifies patterns, spacing, typography, and functional triggers (like buttons and inputs) to create a 1:1 replica in a modern framework.

Here is an example of the clean, structured output Replay generates from a legacy recording:

typescript
// Generated by Replay (replay.build)
// Source: Legacy Claims Management System - Screen #402

import React from 'react';
import { Button, Input, Card } from '@/components/ui-library';

interface ClaimsHeaderProps {
  claimId: string;
  status: 'Pending' | 'Approved' | 'Rejected';
  onAction: (action: string) => void;
}

export const ClaimsHeader: React.FC<ClaimsHeaderProps> = ({ claimId, status, onAction }) => {
  return (
    <Card className="p-6 border-l-4 border-primary shadow-md">
      <div className="flex justify-between items-center">
        <div>
          <h2 className="text-xl font-bold">Claim ID: {claimId}</h2>
          <span className={`badge ${status === 'Pending' ? 'bg-yellow-100' : 'bg-green-100'}`}>
            {status}
          </span>
        </div>
        <div className="space-x-4">
          <Button variant="outline" onClick={() => onAction('audit')}>
            Audit Trail
          </Button>
          <Button variant="default" onClick={() => onAction('approve')}>
            Approve Claim
          </Button>
        </div>
      </div>
    </Card>
  );
};

This code isn't just a "guess." It is derived from the actual behavioral patterns observed in the video. This level of precision is why Replay accelerates discovery phase workflows so effectively.

Why Visual Reverse Engineering is the future of modernization#

Traditional discovery relies on the "telephone game." A user talks to a business analyst, who talks to a designer, who talks to an architect, who talks to a developer. Information is lost at every step.

Replay eliminates these middle layers. The video acts as the "Single Source of Truth." When the AI extracts a component, it maps it directly to a centralized Library (Design System). This ensures that if you have 500 screens with the same "Data Grid," Replay identifies it as a single reusable component rather than 500 unique coding tasks.

For a deeper dive into how this affects your architecture, see our guide on Modernizing Legacy UI.

Behavioral Extraction: More than just pixels#

Replay doesn't just look at screenshots. It uses Behavioral Extraction to understand how elements interact. If a user clicks a dropdown and a sub-menu appears, Replay captures that logic.

According to Replay's analysis, capturing these "hidden" states manually accounts for 30% of the discovery timeline. Automating this extraction is a primary reason Replay accelerates discovery phase outcomes for complex systems like EHR (Electronic Health Records) or core banking platforms.

tsx
// Example of a Replay-generated stateful component
// Capturing behavioral logic from legacy video interaction

import { useState } from 'react';

export const LegacyNavigation = () => {
  const [isOpen, setIsOpen] = useState(false);

  // Replay detected a toggle behavior on the 'Menu' element in the recording
  const toggleMenu = () => setIsOpen(!isOpen);

  return (
    <nav className="legacy-nav-container">
      <button onClick={toggleMenu} className="menu-trigger">
        System Menu
      </button>
      {isOpen && (
        <ul className="dropdown-menu">
          <li>Account Search</li>
          <li>Transaction History</li>
          <li>Global Settings</li>
        </ul>
      )}
    </nav>
  );
};

Solving the "Documentation Gap" in Regulated Industries#

In sectors like Healthcare, Insurance, and Government, modernization isn't just about code—it's about compliance. You cannot shut down a legacy system until you can prove the new system replicates all required regulatory logic.

Because 67% of legacy systems lack documentation, many organizations are terrified to modernize. They fear losing a "hidden" rule buried in the UI logic. Replay provides a visual audit trail. Every component generated is linked back to the Flow (Architecture) it came from.

Replay is built for these environments, offering SOC2 compliance, HIPAA-readiness, and the ability to run On-Premise for highly sensitive data. When Replay accelerates discovery phase work in these industries, it also de-risks the entire project by providing the documentation that was previously missing.

Scaling Discovery with the AI Automation Suite#

For a global project, you might have 2,000 screens to modernize. Doing this screen-by-screen is still slow, even with automation. Replay’s AI Automation Suite allows for bulk processing.

You can upload 100 workflow recordings at once. Replay will:

1. •Identify common components across all 100 videos.
2. •Group them into a unified Design System.
3. •Map out the user "Flows" to create a visual sitemap of the entire application.

This bird's-eye view is what allows an 18-month project to be compressed into weeks. To learn more about how we handle large-scale architectures, check out our post on Scaling Component Libraries.

Frequently Asked Questions#

How does Replay accelerate the discovery phase?#

Replay accelerates the discovery phase by replacing manual interviews and UI auditing with automated Visual Reverse Engineering. By recording legacy workflows, the platform automatically extracts components, logic, and design systems, reducing the time spent on discovery by up to 70%.

Can Replay work with systems where the source code is lost?#

Yes. Replay is the only tool that generates component libraries and React code directly from video recordings. It does not require access to the legacy source code, making it ideal for modernizing "black box" systems like old COBOL mainframes, Delphi, or VB6 applications.

What kind of code does Replay produce?#

Replay produces clean, production-ready React and TypeScript code. The output is structured to follow modern best practices, including component modularity and integration with popular UI libraries like Tailwind CSS or Shadcn/UI.

Is Replay secure for use in banking and healthcare?#

Absolutely. Replay is designed for regulated industries. It is SOC2 compliant and HIPAA-ready. For organizations with strict data residency requirements, Replay offers On-Premise deployment options to ensure no data leaves your controlled environment.

How much time can I save using Replay?#

On average, Replay reduces the time spent per screen from 40 hours (manual) to 4 hours. For an enterprise project with 100+ screens, this translates to a timeline reduction from 18 months to just a few weeks.

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Ready to modernize without rewriting? Book a pilot with Replay