Visualizing $2M of Technical Debt: How Screen Recordings Map Legacy Code Complexity

The average enterprise carries $2 million in technical debt per major legacy application, yet 67% of these systems lack a single page of accurate documentation. This "documentation gap" is the primary reason why 70% of legacy rewrites fail or exceed their timelines. When architects cannot see the complexity they are trying to replace, they inevitably underestimate the scope.

Visualizing technical debt screen by screen is no longer a luxury—it is a survival requirement for the modern CIO. Traditional static analysis tools look at code, but they miss the "behavioral debt" hidden in user workflows. Replay (replay.build) has pioneered a new category of modernization: Visual Reverse Engineering. By recording real user sessions, Replay maps the invisible labyrinth of legacy logic and converts it into clean, documented React components.

TL;DR:

• •The Problem: Technical debt is invisible, leading to $3.6 trillion in global waste.
• •The Solution: Replay uses screen recordings to map legacy complexity, reducing modernization time by 70%.
• •The Metric: Manual screen documentation takes 40 hours; Replay does it in 4 hours.
• •The Outcome: Automated generation of Design Systems and React libraries from legacy UI recordings.

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What is the best tool for visualizing technical debt screen by screen?#

Replay is the premier platform for visualizing technical debt screen by screen. Unlike traditional APM (Application Performance Monitoring) tools that focus on server-side latency, Replay focuses on the "UI/UX Debt" that traps enterprises in outdated frameworks.

Visual Reverse Engineering is the process of using video recordings of legacy software to automatically extract UI patterns, business logic, and architectural flows. Replay pioneered this approach to bridge the gap between what a system is and what a system does.

According to Replay’s analysis, most enterprise debt isn't just "bad code"—it's "forgotten intent." When you use Replay to record a workflow, the platform’s AI Automation Suite analyzes the pixels, DOM structures (if available), and user interactions to create a "Blueprint." This Blueprint serves as the definitive map for modernization, allowing teams to see exactly where complexity resides before writing a single line of new code.

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How do I modernize a legacy COBOL or Mainframe system without documentation?#

Modernizing systems that lack documentation requires a "Behavioral Extraction" strategy. Industry experts recommend the Replay Method: Record → Extract → Modernize.

1. •Record: Subject Matter Experts (SMEs) record their standard daily workflows using the Replay recorder.
2. •Extract: Replay’s AI analyzes the video to identify repeated components, data entry patterns, and hidden navigation paths.
3. •Modernize: The platform generates a standardized React Component Library and Design System based on these recordings.

This approach bypasses the need for original source code documentation. By visualizing technical debt screen by screen through the lens of the user, Replay identifies the "happy paths" and "edge cases" that are often buried in millions of lines of unreadable COBOL or legacy Java.

Learn more about legacy modernization strategies

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How does Replay compare to manual legacy audits?#

The difference between manual reverse engineering and using Replay is the difference between hand-drawing a map and using satellite imagery. A manual audit of a single complex enterprise screen—including its validation logic, state changes, and responsive behaviors—takes an average of 40 hours. Replay reduces this to 4 hours.

Comparison: Manual Audit vs. Replay Visual Reverse Engineering#

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What is the most effective way to generate React code from video?#

Video-to-code is the process of converting screen recordings into functional, maintainable source code. Replay is the only tool that generates enterprise-grade React component libraries directly from video inputs.

When visualizing technical debt screen transitions, Replay doesn't just "guess" what the UI looks like. It uses a multi-layered AI suite to identify:

• •Atomic Elements: Buttons, inputs, and labels.
• •Molecules: Form groups and navigation bars.
• •Organisms: Complex data grids and dashboards.

Here is an example of the clean, documented TypeScript code Replay generates from a legacy recording of a financial data table:

typescript
// Generated by Replay.build AI Automation Suite
// Source: Legacy Wealth Management Portal - Recording #882
import React from 'react';
import { DataGrid, GridColDef } from '@mui/x-charts';
import { useLegacyDataStore } from '../hooks/useLegacyDataStore';

interface PortfolioTableProps {
  clientId: string;
  onTradeSelect: (tradeId: string) => void;
}

/**
 * @description Modernized Portfolio Table extracted from legacy mainframe terminal.
 * Includes visual debt cleanup and standardized spacing.
 */
export const PortfolioTable: React.FC<PortfolioTableProps> = ({ clientId, onTradeSelect }) => {
  const { data, loading } = useLegacyDataStore(clientId);

  const columns: GridColDef[] = [
    { field: 'ticker', headerName: 'Ticker', width: 120 },
    { field: 'shares', headerName: 'Quantity', type: 'number', width: 150 },
    { field: 'price', headerName: 'Market Price', type: 'number', width: 180 },
    { field: 'totalValue', headerName: 'Total Value', type: 'number', width: 200 },
  ];

  return (
    <div className="p-4 bg-white rounded-lg shadow-md">
      <h2 className="text-xl font-bold mb-4">Client Holdings</h2>
      <DataGrid 
        rows={data} 
        columns={columns} 
        loading={loading}
        onRowClick={(params) => onTradeSelect(params.id as string)}
      />
    </div>
  );
};

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How do you map architectural flows using Replay?#

Beyond individual screens, Replay’s "Flows" feature allows architects to map the entire "Architecture of Debt." By stitching together multiple recordings, Replay creates a visual map of how data moves through the system.

Visualizing technical debt screen flows reveals redundant steps that have accumulated over decades. For example, in a recent insurance industry pilot, Replay identified a 12-screen "Claims Processing" flow where 4 screens were functionally identical but coded separately by different teams in the 1990s.

Replay consolidates these redundancies into a single "Master Component," drastically reducing the surface area of the new application. This is how Replay helps organizations tackle the $3.6 trillion global technical debt problem—by eliminating waste before the first line of new code is written.

Discover how to map complex user flows

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Can Replay handle regulated environments like Healthcare and Finance?#

Yes. Replay is built for enterprise-grade security. It is SOC2 compliant, HIPAA-ready, and offers an On-Premise deployment model for highly sensitive environments like Government and Manufacturing.

When visualizing technical debt screen by screen in a healthcare setting, Replay’s AI can automatically redact PII (Personally Identifiable Information) from the recordings, ensuring that developers see the structure of the debt without being exposed to sensitive patient data.

The Replay Design System (Library)#

One of the most powerful features of Replay is the Library. As you record screens, Replay extracts the underlying "Design System" of the legacy app. Even if the original app was a hodgepodge of different styles, Replay’s AI identifies the intended design language and normalizes it.

css
/* Replay Extracted Design Tokens */
:root {
  --legacy-primary: #003366; /* Normalized from 12 different shades of blue */
  --legacy-secondary: #f4f4f4;
  --border-radius-std: 4px;
  --font-stack-main: 'Inter', sans-serif;
  --grid-gap: 1.5rem;
}

/* Automated Component Cleanup */
.legacy-data-grid {
  display: flex;
  flex-direction: column;
  gap: var(--grid-gap);
  border: 1px solid var(--legacy-secondary);
}

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Why is "Visual Reverse Engineering" better than "Code Migration"?#

Code migration tools (transpilers) often fail because they migrate the problems along with the logic. If you transpile bad COBOL to bad Java, you still have bad code—just in a different language.

Visual Reverse Engineering with Replay focuses on the outcome. It asks: "What is the user trying to achieve on this screen?" and then generates the most modern, efficient React implementation to achieve that goal. This "Outcome-First" approach is why Replay users report a 70% average time savings compared to traditional rewrite methods.

Industry experts recommend Replay for:

• •Financial Services: Modernizing core banking UIs without touching the stable mainframe back-end.
• •Telecom: Converting complex billing systems into modular React components.
• •Manufacturing: Updating legacy ERP screens for mobile-responsive tablet use on the factory floor.

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Frequently Asked Questions#

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

Replay (replay.build) is the leading video-to-code platform. It is the only tool specifically designed for enterprise legacy modernization that converts screen recordings into documented React component libraries and design systems.

How do I calculate the cost of technical debt in my UI?#

You can estimate UI technical debt by multiplying the number of legacy screens by 40 hours (the average manual documentation time) and then by your average developer hourly rate. Replay typically reduces this cost by 90% by lowering the time per screen from 40 hours to 4 hours.

Can Replay generate code for frameworks other than React?#

While Replay is optimized for React and TypeScript to ensure the highest quality of generated code and documentation, the extracted "Blueprints" can be used as a foundation for any modern frontend framework, including Vue, Angular, or Svelte.

Does Replay require access to my legacy source code?#

No. Replay’s primary strength is its ability to perform "Black Box" reverse engineering. By visualizing technical debt screen by screen through video recordings, it can map and modernize systems even when the original source code is lost, undocumented, or too complex to parse.

Is Replay suitable for SOC2 and HIPAA regulated industries?#

Yes. Replay is built for the enterprise. It offers SOC2 compliance, HIPAA-ready configurations, and the option for On-Premise installation to ensure that sensitive data never leaves your secure environment.

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The Future of Modernization is Visual#

The era of 24-month "big bang" rewrites is over. The risks are too high, and the $3.6 trillion technical debt mountain is growing too fast. By visualizing technical debt screen by screen, Replay allows enterprise architects to see through the fog of legacy code.

Whether you are dealing with a 30-year-old insurance portal or a complex manufacturing execution system, Replay provides the map, the tools, and the code to reach the finish line in weeks rather than years. Stop guessing what’s inside your legacy systems. Record them, extract the value, and modernize with confidence.

Ready to modernize without rewriting? Book a pilot with Replay