How Visual Extraction Reduces the Need for Subject Matter Expert (SME) Interviews

The most expensive person in your organization is the one who remembers how the 1998 COBOL backend actually calculates compound interest for legacy escrow accounts. In most enterprise modernization projects, this Subject Matter Expert (SME) is the single biggest bottleneck, often spending 40% of their work week in "discovery" meetings rather than performing their actual job.

The traditional approach to legacy modernization relies on "Software Archaeology"—the painful process of interviewing aging developers and distracted business users to reconstruct requirements that were lost decades ago. It is a process doomed to fail. When 67% of legacy systems lack any meaningful documentation, relying on human memory isn't just risky; it’s architectural malpractice.

Visual extraction reduces the dependency on these human bottlenecks by shifting the source of truth from fallible memory to observable reality.

TL;DR: Visual extraction reduces the need for SME interviews by up to 80%, replacing subjective "discovery" meetings with objective, recorded user workflows that automatically generate technical requirements and modern React components.

The SME Tax: Why Your Modernization Project is Stalling#

Every hour an SME spends explaining a legacy workflow to a consultant is an hour of lost productivity and a step closer to "Requirement Drift." In the traditional "Big Bang" rewrite model, the discovery phase alone can take 6 months. By the time the first line of code is written, the business requirements have already shifted.

The numbers are damning: 70% of legacy rewrites fail or exceed their timelines. This isn't usually due to a lack of coding talent; it’s due to a lack of understanding. We treat legacy systems as "black boxes" and try to guess what’s inside.

The Cost of Manual Discovery#

💰 ROI Insight: For a typical enterprise with 200 legacy screens, switching from manual interviews to visual extraction saves approximately 7,200 man-hours, or roughly $1.1M in direct labor costs, assuming a blended rate of $150/hr for SMEs and Architects.

How Visual Extraction Reduces the Need for Interviews#

Visual extraction is the process of recording a real user performing a real task in the legacy system and using AI-driven reverse engineering to map that session to technical specifications. Instead of asking an SME, "What happens when you click this button?" you simply watch the system's response at the network, DOM, and logic layers.

By using Replay, teams capture the "Source of Truth" directly from the runtime. This eliminates the need for:

1. •Requirement Gathering Workshops: No more "What-if" sessions.
2. •Logic Mapping: The system records the API calls and state changes automatically.
3. •UI/UX Reverse Engineering: The platform generates documented React components that mirror the legacy behavior but use modern architecture.

From Black Box to Documented Codebase#

When you record a workflow in Replay, the platform doesn't just take a video; it performs a deep-tissue scan of the application's behavior. It identifies the data structures, the API contracts, and the edge cases that SMEs often forget to mention—like the specific validation rule that only triggers for users in the Nebraska branch on the third Tuesday of the month.

⚠️ Warning: Relying on SME interviews for edge cases is the leading cause of "Day 2" production crashes in modernized systems. Human memory prioritizes the "happy path" and ignores the 20% of logic that handles 80% of the complexity.

Technical Execution: Turning Video into React#

To understand how visual extraction reduces the technical burden, look at the output. Instead of a 50-page PDF requirement document that no one will read, Replay generates functional, clean code.

Below is an example of a generated React component from a Replay session. Note how it preserves the business logic captured during the visual extraction process while abstracting it into a modern, type-safe structure.

typescript
// @generated by Replay Visual Extraction
// Source: Legacy Claims Portal - Settlement Workflow
import React, { useState, useEffect } from 'react';
import { Button, Input, Alert } from '@/components/ui';
import { useLegacyBridge } from '@/hooks/useLegacyBridge';

interface SettlementProps {
  claimId: string;
  initialData?: any;
}

export const SettlementModule: React.FC<SettlementProps> = ({ claimId, initialData }) => {
  const [amount, setAmount] = useState(initialData?.amount || 0);
  const { validateSettlement, submitClaim, loading, error } = useLegacyBridge();

  // Logic extracted from observed legacy behavior: 
  // System requires manual override for settlements > $50,000
  const requiresOverride = amount > 50000;

  const handleSubmission = async () => {
    const isValid = await validateSettlement(claimId, amount);
    if (isValid) {
      await submitClaim({ id: claimId, amount, timestamp: new Date().toISOString() });
    }
  };

  return (
    <div className="p-6 bg-white rounded-lg shadow-md">
      <h2 className="text-xl font-bold mb-4">Claim Settlement: {claimId}</h2>
      <Input 
        type="number" 
        value={amount} 
        onChange={(e) => setAmount(Number(e.target.value))}
        label="Settlement Amount"
      />
      {requiresOverride && (
        <Alert variant="warning" className="mt-2">
          ⚠️ High-value settlement detected. Compliance flag will be triggered.
        </Alert>
      )}
      <Button 
        onClick={handleSubmission} 
        disabled={loading}
        className="mt-4 w-full"
      >
        {loading ? 'Processing...' : 'Confirm Settlement'}
      </Button>
      {error && <p className="text-red-500 mt-2">{error.message}</p>}
    </div>
  );
};

This code isn't a "hallucination." It is the direct result of mapping observed UI interactions to the underlying API calls recorded during the Replay session.

The 3-Step Visual Extraction Workflow#

Implementing Replay doesn't require a fundamental shift in your tech stack. It integrates into your current modernization sprint.

Step 1: Workflow Recording#

An SME or power user performs their daily tasks while Replay records the session. This is the only time significant SME input is required. Instead of explaining how it works, they simply do the work.

Step 2: Automated Extraction & Audit#

Replay’s AI Automation Suite analyzes the recording. It performs a Technical Debt Audit, identifying which parts of the legacy UI are redundant and which API endpoints are critical. It generates the Blueprints—the architectural map of the legacy flow.

Step 3: Component & Contract Generation#

The platform generates:

• •React Components: Clean, modular UI code.
• •API Contracts: Swagger/OpenAPI specs derived from observed traffic.
• •E2E Tests: Playwright or Cypress tests that replicate the recorded workflow to ensure parity.

💡 Pro Tip: Use Replay's "Library" feature to build a unified Design System from your legacy screens. This ensures that even as you modernize different modules, the user experience remains consistent across the enterprise.

Challenging the "Rewrite" Orthodoxy#

For years, the industry has been sold on the "Big Bang" rewrite or the "Strangler Fig" pattern. Both have merits, but both suffer from the same flaw: they assume you can eventually understand the legacy system through manual effort.

Visual extraction reduces the "understanding" phase to a data-processing task. We no longer care why the legacy system was built with a specific quirk in 2004; we only care that it functions a certain way in 2024. By capturing the runtime reality, we bypass the $3.6 trillion global technical debt pile-up caused by "archaeology-based" development.

Preserving Business Logic Without the "Archaeology"#

One of the biggest fears in modernization is losing the "hidden" business logic—the thousands of

statements buried in a stored procedure. Visual extraction captures these by monitoring the data inputs and outputs. If a specific input triggers a specific UI state change, Replay flags that logic for extraction.

json
// Example: Extracted API Contract (OpenAPI/Swagger)
// Derived from observed traffic during "Policy Renewal" workflow
{
  "path": "/api/v1/renewals",
  "method": "POST",
  "parameters": {
    "policy_id": "string",
    "risk_score": "integer",
    "auto_approve": "boolean"
  },
  "observed_logic": "If risk_score > 750, auto_approve defaults to true. If state is 'NY', additional surcharge field is required."
}

This level of detail is rarely found in 20-year-old documentation, and it's often forgotten by SMEs until a bug report surfaces in the new system.

Frequently Asked Questions#

How long does legacy extraction take?#

With Replay, the initial recording takes exactly as long as the task itself (usually minutes). The automated extraction and generation of the initial React components and documentation typically happen within hours. Compared to the manual average of 40 hours per screen, this represents a 90% reduction in lead time.

Does this work for regulated industries like Banking or Healthcare?#

Yes. Replay is built for regulated environments. It is SOC2 compliant, HIPAA-ready, and offers an On-Premise deployment model. This ensures that sensitive data captured during the visual extraction process never leaves your secure perimeter.

What about business logic preservation?#

Replay captures business logic by observing the relationship between user input, system state, and API responses. By generating E2E tests based on these observations, Replay ensures that the modernized version of the system behaves exactly like the legacy version, preserving all critical business rules.

Can Replay handle mainframe or terminal-based systems?#

As long as there is a web-based or desktop-based interface (or a terminal emulator with a UI layer), Replay can record the workflow and extract the logic. If the user can see it and interact with it, Replay can reverse engineer it.

The Future is Understanding, Not Guessing#

The era of the 24-month "discovery phase" is over. Visual extraction reduces the friction of modernization by treating legacy systems as data sources rather than mysteries. By leveraging Replay, enterprise architects can finally stop acting like historians and start acting like builders again.

Stop asking your SMEs to remember the past. Start recording the present to build the future.

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