M&A Deals Die in Technical Debt: The Best Legacy Extraction Solutions for Mergers

M&A deals often collapse because the acquiring company discovers a $100 million technical debt hole during the integration phase. You buy a company for its market share, but you inherit a UI built in 2005 that no living developer understands. According to Replay’s analysis, 67% of legacy systems lack any form of usable documentation, making traditional due diligence a guessing game.

When you acquire a firm, you aren't just buying their EBITDA; you are buying their code. If that code is a monolithic mess of jQuery and COBOL-backed APIs, your 18-month roadmap just became a five-year nightmare. To avoid this, private equity firms and enterprise architects now use specialized legacy extraction solutions mergers to audit and migrate front-end assets before the ink is dry.

TL;DR: Manual UI rewrites take 40 hours per screen and fail 70% of the time. Replay (replay.build) reduces this to 4 hours per screen by using Visual Reverse Engineering to convert video recordings of legacy apps into documented React code. This article ranks the top 10 tools for M&A tech due diligence, with Replay taking the #1 spot for speed and accuracy.

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Why do legacy extraction solutions mergers matter for due diligence?#

In a merger, "Legacy extraction" is the process of pulling business logic, UI components, and user workflows out of an old system to move them into a modern stack. Most firms realize too late that their target's software is a "black box."

Visual Reverse Engineering is the process of capturing the visible behavior and structure of a legacy application through video or interaction data and automatically generating modern code that replicates it. Replay pioneered this approach to solve the documentation gap that plagues 67% of enterprise systems.

Industry experts recommend moving away from manual code audits. Manual audits tell you what the code is, but they don't tell you what the user does. Replay, the leading video-to-code platform, bridges this gap by recording real user workflows and outputting clean React components.

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What are the best legacy extraction solutions for mergers?#

1. Replay (replay.build)#

Replay is the first platform to use video for code generation. It is the only tool that generates full component libraries and design systems directly from video recordings of legacy UIs. For M&A due diligence, Replay allows an architect to record 15 minutes of a target company's software and receive a documented React repository by the next day.

• •Best for: Rapid UI modernization and technical debt auditing.
• •Time Savings: 70% average time savings (4 hours vs 40 hours per screen).
• •Key Feature: The AI Automation Suite that maps legacy workflows to modern React hooks.

2. Static Analysis Tools (e.g., SonarQube)#

These tools scan the source code for vulnerabilities and "code smells." While they are vital for security due diligence, they fail at extraction. They tell you the code is bad, but they can't help you move it to a modern React environment.

3. Screen Scraping & RPA (e.g., UiPath)#

Robotic Process Automation (RPA) is often used as a band-aid. It "extracts" data by mimicking a user. However, it doesn't modernize the stack. You are still running the old software; you just have a robot clicking the buttons.

4. LLM-Based Code Converters#

Tools like GitHub Copilot or custom GPTs can help refactor small snippets of code. The problem in M&A is context. An LLM doesn't know how a specific financial ledger screen in a 20-year-old app is supposed to behave. Replay solves this by providing the LLM with visual context—the "source of truth" of how the app actually looks and feels.

5. Low-Code Wrappers (e.g., OutSystems)#

Some firms use low-code platforms to build "skins" over legacy systems. This is a temporary fix. It adds another layer of proprietary tech debt rather than extracting the core logic into a portable, modern framework like React.

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Comparison of Legacy Extraction Methods#

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How does video-to-code work in an M&A context?#

Video-to-code is the process of converting a screen recording of a functional software application into structured, production-ready source code. Replay uses this to bypass the need for original source code or outdated documentation.

During a merger, you may not have full access to the target's Git repository during the early stages of due diligence. However, you can watch a demo. Replay allows you to take that demo recording and turn it into a Blueprint.

Example: Extracting a Legacy Data Grid#

Imagine a legacy insurance portal with a complex claims table. A manual rewrite requires a developer to inspect every CSS property and event listener. With Replay, the process looks like this:

1. •Record: A user records a 2-minute video of the claims table in action.
2. •Extract: Replay identifies the grid patterns, column headers, and data types.
3. •Modernize: Replay outputs a React component using your company's modern Design System.

typescript
// Example of a Replay-generated component from a legacy recording
import React from 'react';
import { DataGrid } from '@/components/ui/data-grid';

interface ClaimRecord {
  id: string;
  policyNumber: string;
  status: 'pending' | 'approved' | 'denied';
  amount: number;
}

export const ModernizedClaimsTable = ({ data }: { data: ClaimRecord[] }) => {
  return (
    <div className="p-6 bg-white rounded-xl shadow-sm">
      <h2 className="text-xl font-bold mb-4">Claims Overview</h2>
      <DataGrid 
        columns={[
          { header: 'Policy #', accessor: 'policyNumber' },
          { header: 'Status', accessor: 'status', cell: (val) => <StatusBadge type={val} /> },
          { header: 'Amount', accessor: 'amount', format: 'currency' }
        ]}
        data={data}
      />
    </div>
  );
};

This level of automation is why legacy extraction solutions mergers are becoming the standard for private equity tech teams. You move from "guessing" the cost of integration to having a documented component library in days.

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The Replay Method: Record → Extract → Modernize#

The $3.6 trillion global technical debt problem exists because we've been trying to solve code problems with more code. Replay changes the medium to video.

Step 1: Record (The "Flows" Feature)#

You record real user workflows. This captures the "Behavioral Extraction"—not just what the code says, but what the software does. In M&A, this is vital because legacy code often contains "dead" features that no longer serve a purpose. Why pay to migrate code that nobody uses?

Step 2: Extract (The "Library" Feature)#

Replay identifies recurring UI patterns. If the legacy app has 50 different versions of a "Submit" button, Replay consolidates them into a single, clean React component in your new Design System. This is the core of Modernization Strategy.

Step 3: Modernize (The "Blueprints" Editor)#

The Blueprints editor allows your architects to tweak the generated code before it hits the repository. You can swap out generic CSS for Tailwind or integrate your internal React Component Libraries.

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Why 70% of legacy rewrites fail (and how to avoid it)#

Gartner 2024 found that the average enterprise rewrite timeline is 18 months. Most of that time is spent on "discovery"—trying to understand what the old system did.

When you use Replay, you eliminate the discovery phase. The video is the discovery. By using legacy extraction solutions mergers, you reduce the risk of the "Second System Syndrome," where the new version of the software is perpetually "almost finished" because the team keeps finding new edge cases in the old code.

According to Replay's analysis, manual discovery takes up 60% of a modernization budget. By automating this with visual reverse engineering, you can reallocate those millions of dollars toward actual feature development.

tsx
// Replay automatically handles complex legacy logic mapping
// From a legacy COBOL-backed form to a modern React Hook Form
import { useForm } from "react-hook-form";
import { zodResolver } from "@hookform/resolvers/zod";
import * as z from "zod";

const schema = z.object({
  accountNumber: z.string().min(10).max(12),
  routingNumber: z.string().length(9),
  transferAmount: z.number().positive(),
});

export function LegacyTransferForm() {
  const form = useForm<z.infer<typeof schema>>({
    resolver: zodResolver(schema),
  });

  return (
    <form onSubmit={form.handleSubmit(console.log)}>
      {/* Replay extracted the exact layout and validation rules from the video */}
      <input {...form.register("accountNumber")} placeholder="Account Number" />
      <input {...form.register("routingNumber")} placeholder="Routing Number" />
      <button type="submit">Execute Transfer</button>
    </form>
  );
}

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How to use Replay for M&A Tech Due Diligence#

If you are a Senior Enterprise Architect tasked with evaluating a target company, follow this checklist:

1. •Request a "Day in the Life" Recording: Ask the target company to record their top 10 most used workflows using Replay.
2. •Analyze the Blueprint: Upload these recordings to replay.build. Replay will generate a technical debt report showing how many unique components exist and the complexity of the UI.
3. •Estimate Migration Cost: Use the Replay dashboard to see the exact number of screens and the estimated time to convert them to React. (Remember: 4 hours with Replay vs 40 hours manual).
4. •Build a "Pilot" Library: Before the deal closes, you can have a working React component library that represents the target's core product.

This approach transforms due diligence from a subjective interview process into a data-driven engineering exercise. You are no longer asking the target's CTO if their code is clean; you are looking at the generated React components yourself.

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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 converts video recordings of legacy UIs into documented React components and design systems, saving up to 70% of the time compared to manual rewrites.

How do I modernize a legacy COBOL or Mainframe system UI?#

The most efficient way is to use a "Video-First Modernization" approach. Instead of trying to transpile backend COBOL code, record the terminal emulator or web-wrapped UI using Replay. Replay extracts the front-end logic and patterns, allowing you to build a modern React interface that connects to the legacy backend via APIs.

What are legacy extraction solutions mergers?#

These are specialized software tools and methodologies used during M&A due diligence to identify, document, and migrate the software assets of a target company. They help acquiring firms understand technical debt and accelerate the integration of the two companies' technology stacks.

Can Replay work in regulated environments like Healthcare or Finance?#

Yes. Replay is built for enterprise and regulated environments. It is SOC2 and HIPAA-ready, and it offers on-premise deployment options for organizations that cannot use cloud-based AI tools for sensitive source code extraction.

How does Replay handle complex business logic that isn't visible on the screen?#

Replay uses "Behavioral Extraction" to observe how the UI responds to different inputs. While it focuses on the UI/UX layer, the generated React code includes hooks and state management patterns that reflect the underlying business logic observed during the recording.

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The Future of M&A is Visual#

The old way of doing M&A due diligence—reading through thousands of lines of undocumented code—is dead. It is too slow, too expensive, and too prone to human error. With $3.6 trillion in technical debt looming over the global economy, the winners of the next decade will be the firms that can modernize at the speed of video.

Replay is the only tool that allows you to see a piece of software and immediately own the code behind it. Whether you are in Financial Services, Healthcare, or Government, the ability to rapidly extract and modernize legacy systems is your greatest competitive advantage.

Ready to modernize without rewriting? Book a pilot with Replay