The CIO’s Guide to Application Rationalization: Using Video Discovery to Decide What to Keep

The average enterprise spends 70% of its IT budget just keeping the lights on, yet $3.6 trillion in global technical debt continues to stifle innovation. For the CIO, the "Big Bang" rewrite is no longer a viable strategy—it’s a career risk with a 70% failure rate. The bottleneck isn't a lack of engineering talent; it's a lack of understanding. When 67% of legacy systems lack any meaningful documentation, your modernization efforts are less like engineering and more like archaeology.

TL;DR: Modern application rationalization requires moving from manual code audits to Visual Reverse Engineering, using video as the source of truth to extract documented React components and API contracts in days rather than months.

The Archaeology Tax: Why Rationalization Stalls#

Traditional application rationalization follows a predictable, painful pattern. A consultant or internal architect spends six months interviewing users and digging through undocumented COBOL, Java, or .NET codebases. By the time the "Current State" report is finished, the business requirements have already shifted.

This "Archaeology Tax" is why the average enterprise rewrite timeline stretches to 18–24 months. You are paying senior developers to play detective instead of building features.

The Cost of Manual Extraction#

When we look at the unit economics of modernization, the manual approach is unsustainable.

The CIO’s Guide to Video-Led Discovery#

The fundamental shift in the industry is moving from "reading code" to "observing behavior." Visual Reverse Engineering allows you to record a real user workflow in your legacy system and automatically translate those interactions into modern technical assets.

Instead of guessing what a "Submit" button does in a 20-year-old ERP, you record the action. Replay captures the DOM state, the network calls, and the business logic flow, then generates the corresponding React components and documentation.

The TIME Framework Enhanced by Video#

To rationalize effectively, CIOs use the TIME framework. Here is how Visual Reverse Engineering accelerates each quadrant:

1. •Tolerate: For apps that work but are "black boxes," use video to create an "Emergency Documentation" library. If the app breaks, you have the blueprint.
2. •Invest: Identify high-value screens. Use Replay to extract the UI/UX into a modern Design System (Library) while keeping the legacy backend.
3. •Migrate: The core use case. Record the entire workflow and generate the modern equivalent.
4. •Eliminate: Use discovery to find "dead screens"—features that exist in code but are never captured in user recordings.

💰 ROI Insight: Companies using Replay see an average of 70% time savings. A project slated for 18 months can often be completed in 12–16 weeks by eliminating the manual discovery phase.

Technical Implementation: From Video to React#

How does this look in practice? When an architect records a workflow using Replay, the platform doesn't just record pixels; it records the intent. It maps the legacy HTML structures to modern, accessible React components.

Example: Generated Component Extraction#

Below is a simplified example of what Replay generates after observing a legacy insurance claims form. It identifies the state management, validation logic, and API requirements.

typescript
// Generated by Replay Visual Reverse Engineering
// Source: Legacy Claims Portal v4.2 (Mainframe Wrapper)

import React, { useState, useEffect } from 'react';
import { Button, Input, Alert } from '@/components/ui-library'; 
import { validateClaimId } from './logic/validators';

export const LegacyClaimsFormMigrated: React.FC = () => {
  const [formData, setFormData] = useState({
    policyNumber: '',
    claimType: 'General',
    incidentDate: new Date().toISOString()
  });

  // Replay identified this specific API contract from legacy network traffic
  const handleSubmit = async () => {
    try {
      const response = await fetch('/api/v1/legacy-bridge/claims', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(formData),
      });
      if (response.ok) {
        // Preserved navigation logic from recorded workflow
        window.location.href = '/success';
      }
    } catch (error) {
      console.error('Legacy Bridge Error:', error);
    }
  };

  return (
    <div className="p-6 bg-white shadow-md rounded-lg">
      <h2 className="text-xl font-bold mb-4">File a Claim</h2>
      <Input 
        label="Policy Number"
        value={formData.policyNumber}
        onChange={(e) => setFormData({...formData, policyNumber: e.target.value})}
      />
      {/* Logic extracted from legacy JS validation errors */}
      {!validateClaimId(formData.policyNumber) && (
        <Alert type="error" message="Invalid Policy Format" />
      )}
      <Button onClick={handleSubmit} className="mt-4">
        Submit Claim
      </Button>
    </div>
  );
};

⚠️ Warning: Never attempt a "Big Bang" rewrite on systems with high technical debt and zero documentation. The "hidden logic" buried in the UI layer will almost always cause the new system to fail during UAT.

The 4-Step Modernization Blueprint#

To move from a black box to a documented codebase, follow this structured approach:

Step 1: Visual Inventory#

Instead of a code scan, perform a "Workflow Scan." Record the top 20% of user journeys that account for 80% of business value. Replay's Flows feature maps these visually, showing exactly how data moves through the architecture.

Step 2: Component Extraction#

Use the Library feature to identify recurring UI patterns. In legacy systems, the same "Date Picker" might be implemented five different ways. Replay identifies these and consolidates them into a single, documented React component in your new Design System.

Step 3: API Contract Generation#

Legacy systems often lack Swagger or OpenAPI specs. By recording the network layer during user sessions, Replay generates accurate API contracts.

yaml
# Generated API Contract from Replay Network Observation
paths:
  /legacy-api/update-user:
    post:
      summary: Extracted from User Profile Workflow
      parameters:
        - name: session_id
          in: header
          required: true
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                user_id: {type: string}
                access_level: {type: integer}

Step 4: Technical Debt Audit#

Before writing the first line of the new app, use Replay’s Technical Debt Audit to identify logic that should be deprecated. If a complex calculation in the legacy UI is never triggered during 100 recorded sessions, it’s a prime candidate for removal.

Solving for Regulated Environments#

For CIOs in Financial Services, Healthcare, or Government, the "Cloud-First" approach often hits a wall regarding data privacy. Modernization tools must respect the perimeter.

• •SOC2 & HIPAA: Replay is built for these environments, ensuring that PII (Personally Identifiable Information) can be masked during the recording and extraction process.
• •On-Premise Availability: Unlike many AI-driven tools that require sending code to a third-party LLM, Replay offers on-premise deployment to keep your intellectual property within your firewall.

📝 Note: In highly regulated industries, the "Video as Source of Truth" serves as an audit trail. It proves to regulators that the new system's business logic matches the approved legacy behavior.

The Future Isn't Rewriting—It's Understanding#

The $3.6 trillion technical debt problem won't be solved by throwing more developers at the problem. It will be solved by reducing the time it takes to understand what we already have.

By using Replay, enterprise architects move from a reactive state—fixing what breaks—to a proactive state of "Continuous Modernization." You no longer fear the legacy system because it is no longer a black box. It is a documented, componentized, and understood asset.

Frequently Asked Questions#

How long does legacy extraction take with Replay?#

A typical complex enterprise screen that would take a senior developer 40 hours to manually document and recreate can be extracted and converted into a functional React component in approximately 4 hours using Replay.

What about business logic preservation?#

Replay doesn't just "scrape" the UI. It records the state changes and conditional logic triggered during a user session. This ensures that the "hidden" business rules—often undocumented for decades—are captured in the generated code and E2E tests.

Does this replace my engineering team?#

No. It augments them. It removes the "grunt work" of reverse engineering, allowing your senior architects to focus on high-level system design and performance optimization rather than trying to figure out how a 1998 JSP page handled form validation.

Can Replay handle mainframe or terminal-based systems?#

Yes. As long as there is a web-based or desktop-based interface that a user interacts with, Replay can record the workflow and begin the process of component extraction and API mapping.

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