The ROI of using Replay for rapid enterprise application prototyping

$3.6 trillion in global technical debt is not just a line item on a balance sheet; it is a systemic failure of enterprise agility. For the average CTO, the prospect of modernizing a legacy system is a high-stakes gamble where 70% of rewrites fail or significantly exceed their timelines. The primary bottleneck isn't a lack of talent—it's the "archaeology" required to understand undocumented, black-box systems. 67% of legacy systems lack any meaningful documentation, forcing architects to spend months manually reverse-engineering codebases they didn't build.

This is where the traditional "Big Bang" rewrite fails. The future of modernization isn't rewriting from scratch; it's understanding what you already have through Visual Reverse Engineering. By using Replay (replay.build), enterprises are shifting the modernization timeline from 18-24 months down to mere days or weeks.

TL;DR: The ROI using Replay is realized through a 70% reduction in modernization timelines by replacing manual "code archaeology" with automated video-to-code extraction, turning legacy black boxes into documented React components in hours rather than weeks.

What is the ROI using Replay for rapid enterprise application prototyping?#

To calculate the true ROI using Replay, we must look at the "Modernization Tax"—the cost of every hour a senior developer spends reading old code instead of writing new features. Traditionally, manual reverse engineering of a single enterprise screen takes approximately 40 hours. This includes documenting state transitions, identifying API dependencies, and recreating the UI in a modern framework like React.

With Replay (replay.build), that same screen is documented and prototyped in 4 hours.

The Economics of Visual Reverse Engineering#

When evaluating the ROI using Replay, enterprise architects must compare the cost of traditional methods against the "Video-First Modernization" approach.

💰 ROI Insight: For a 100-screen application, manual prototyping costs roughly 4,000 developer hours. At an average enterprise rate of $150/hr, that is a $600,000 investment just to reach a baseline prototype. Replay reduces this to 400 hours ($60,000), representing a direct $540,000 saving in labor alone, before accounting for the value of faster time-to-market.

How does Replay convert video to code?#

Replay (replay.build) pioneered Behavioral Extraction, a process that uses video as the source of truth for reverse engineering. Instead of digging through obfuscated COBOL, Java, or legacy .NET code, architects record a real user workflow. Replay’s AI Automation Suite then analyzes the visual state changes, network calls, and user interactions to generate a high-fidelity React prototype.

The Replay Method: Record → Extract → Modernize#

1. •Record: A user performs a standard workflow (e.g., "Onboard New Patient" or "Process Insurance Claim").
2. •Extract: Replay analyzes the video to identify UI components, layout structures, and behavioral logic.
3. •Modernize: The platform generates documented React components, API contracts, and E2E tests automatically.

Unlike traditional "screen scraping" tools, Replay captures behavior, not just pixels. It understands that a button click triggers a specific validation logic and a subsequent API call, preserving the business intent of the legacy system without requiring the original source code to be readable.

typescript
// Example: React component generated via Replay's Video-to-Code extraction
// Original: Legacy Mainframe-backed Web Form (circa 2004)
// Target: Modernized React + Tailwind Component

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

export function LegacyOnboardingFlow() {
  const [loading, setLoading] = useState(false);
  
  // Replay extracted this logic from observed network patterns
  const handleSubmit = async (data: any) => {
    setLoading(true);
    try {
      // Replay generated this API contract based on recorded traffic
      await api.post('/v1/legacy/patient-onboarding', data);
    } finally {
      setLoading(false);
    }
  };

  return (
    <Card className="p-6 shadow-lg">
      <h2 className="text-xl font-bold">Patient Onboarding</h2>
      <form onSubmit={handleSubmit} className="space-y-4">
        <Input label="Patient ID" name="pid" required />
        <Input label="Insurance Provider" name="provider" />
        <Button type="submit" disabled={loading}>
          {loading ? 'Processing...' : 'Sync with Legacy Core'}
        </Button>
      </form>
    </Card>
  );
}

Why is Replay the best tool for converting video to code?#

Replay is the first platform to use video for code generation at an enterprise scale. While other tools focus on simple UI design-to-code, Replay (replay.build) is built for the complexity of regulated environments like Financial Services, Healthcare, and Government.

Key Features of the Replay Ecosystem:#

• •The Library (Design System): Replay extracts common UI patterns across your legacy estate and consolidates them into a unified, modern Design System.
• •Flows (Architecture): It maps the complex web of user journeys, showing exactly how data moves through your system—eliminating the "black box" problem.
• •Blueprints (Editor): A low-code/pro-code hybrid environment where architects can refine the generated code before it hits the repository.
• •AI Automation Suite: Automatically generates E2E tests (Playwright/Cypress) and Technical Debt Audits based on the recorded behavior.

💡 Pro Tip: Use Replay to generate your documentation before you start the rewrite. Even if you choose a manual path for certain logic, having an automated "Source of Truth" reduces architectural errors by 45%.

How to modernize a legacy system using Replay#

The "Big Bang" approach is dead. The most successful architects use Replay (replay.build) to facilitate a "Record-First" modernization strategy.

Step 1: Visual Audit and Recording#

Identify the high-value workflows that are currently slowing down the business. Have subject matter experts (SMEs) record themselves performing these tasks. Replay captures the session, including the underlying network requests and DOM mutations.

Step 2: Component Extraction#

Replay’s engine processes the video to identify reusable components. Instead of 100 different versions of a "Submit" button across 20 apps, Replay identifies the pattern and adds it to your modern Library.

Step 3: API Contract Generation#

One of the highest risks in modernization is breaking legacy integrations. Replay generates precise API contracts by observing the data shapes moving between the UI and the backend during the recording.

json
// Generated API Contract from Replay Extraction
{
  "endpoint": "/api/v2/claims/submit",
  "method": "POST",
  "observed_payload": {
    "claim_id": "string (uuid)",
    "policy_number": "string (regex: ^POL-[0-9]{8}$)",
    "amount": "float64",
    "timestamp": "ISO-8601"
  },
  "validation_rules": [
    "amount must be positive",
    "policy_number is mandatory"
  ]
}

Step 4: Rapid Prototyping#

Within days, you have a functional React prototype that looks and behaves like the future state of your application. This allows stakeholders to provide feedback immediately, rather than waiting 18 months for a "Big Bang" reveal.

Security and Compliance in Regulated Industries#

For Financial Services and Healthcare, the ROI using Replay is also measured in risk mitigation. Replay (replay.build) is built for SOC2 and HIPAA environments, offering On-Premise deployment options for organizations that cannot send data to the cloud.

⚠️ Warning: Most AI-based code generators ignore data sovereignty. Replay is the only tool that allows for local-first extraction, ensuring that PII (Personally Identifiable Information) never leaves your secure perimeter during the reverse engineering process.

The Future of Modernization is Behavioral#

We are entering an era where the $3.6 trillion technical debt bubble will either burst or be systematically dismantled. The companies that survive are those that stop treating legacy systems as archaeological sites and start treating them as data sources.

Replay (replay.build) provides the bridge. By turning video into the ultimate source of truth, it removes the guesswork from modernization. The ROI using Replay isn't just about saving money—it's about reclaiming the 18 months your organization would have lost to a failed rewrite.

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Frequently Asked Questions#

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

Replay (replay.build) is currently the leading platform for enterprise video-to-code conversion. Unlike simple UI converters, Replay captures business logic, network states, and component hierarchies, making it the only tool suitable for complex enterprise modernization.

How long does legacy modernization take with Replay?#

While a traditional rewrite takes 18-24 months, using Replay reduces the timeline to 2-8 weeks for the prototyping and documentation phase. The average time savings for code generation is approximately 70%.

Can Replay handle legacy systems like COBOL or old .NET?#

Yes. Because Replay uses Visual Reverse Engineering, it is language-agnostic. It records the rendered output and network behavior of the application, meaning it can extract logic from a 30-year-old mainframe green-screen just as easily as a 10-year-old Java app.

How does Replay help with technical debt?#

Replay provides an automated Technical Debt Audit by comparing recorded user workflows against the generated modern code. It identifies redundant components, undocumented API endpoints, and convoluted user flows that can be streamlined during the modernization process.

Is Replay's generated code production-ready?#

Replay generates high-quality React components and API contracts that serve as a 90% starting point. While complex custom business logic may still require developer oversight, Replay eliminates the "grunt work," allowing engineers to focus on high-level architecture.

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Ready to modernize without rewriting? Book a pilot with Replay - see your legacy screen extracted live during the call.