Logic Reconciliation Audits: Comparing Visual Runtimes to Existing Documentation

Your documentation is a lie. In the enterprise world, the delta between what is written in a Confluence page from 2014 and how your legacy COBOL-backed web portal actually behaves in production is often a chasm. When organizations attempt to modernize, they don't just face a coding challenge; they face an archaeological one. This is where logic reconciliation audits comparing the visual runtime to existing documentation become the difference between a successful migration and a $100 million write-off.

According to Replay’s analysis, 67% of legacy systems lack any form of accurate, up-to-date documentation. This "Documentation Debt" forces engineering teams to play a high-stakes game of telephone with retiring subject matter experts (SMEs). If you rely on stale specs to build your new React architecture, you aren't modernizing; you are simply porting bugs into a more expensive framework.

TL;DR: Logic reconciliation audits are essential for identifying discrepancies between legacy system documentation and actual runtime behavior. By using Replay, enterprises can automate this process through Visual Reverse Engineering, reducing the time spent per screen from 40 hours to just 4 hours. This guide explores the methodology of logic reconciliation, the risks of "ghost logic," and how to automate the generation of documented React components from video recordings.

The Technical Debt Crisis: Why Logic Reconciliation Audits Comparing Runtimes is Essential#

The global technical debt has ballooned to a staggering $3.6 trillion. For a Tier-1 financial institution or a healthcare provider, this debt isn't just a line item—it’s a risk vector. When you begin a modernization project, the first instinct is to look at the source code or the requirements docs. However, in systems that have survived multiple acquisitions and decades of "hotfixes," the source code is often too obfuscated to provide a clear picture of the business logic.

Industry experts recommend focusing on the observable behavior of the system. Logic reconciliation audits comparing the intended logic (docs) against the actual logic (runtime) reveal what we call "Ghost Logic"—undocumented edge cases, hardcoded workarounds, and regional validation rules that exist only in the production environment.

Visual Reverse Engineering is the process of capturing these runtimes and converting them into structured data. Instead of manually mapping every button click to a backend service, Replay records the actual user workflow and extracts the underlying logic.

The Cost of Manual Reconciliation#

Historically, a logic audit was a manual, grueling process. A business analyst would sit with a user, record their screen, and then manually type out the requirements. This leads to the "18-month rewrite trap," where the project is obsolete before it even launches.

Learn more about Modernizing Legacy Systems

Understanding the Logic Gap#

When we perform logic reconciliation audits comparing visual runtimes to documentation, we typically find three types of discrepancies:

1. •Orphaned Logic: Features described in the docs that no longer exist in the UI or are broken in the backend.
2. •Shadow Logic: Critical business rules that were added during emergency patches but never made it into the documentation.
3. •State Drift: UI components that behave differently based on data states that the original architects never anticipated.

Video-to-code is the process of taking a visual recording of these states and automatically generating the corresponding frontend logic and component structure. This ensures that the "truth" of the production environment is preserved.

Example: Legacy State Mapping vs. Modern React Implementation#

In a legacy JSP or Silverlight application, logic is often tightly coupled with the DOM. A manual audit might miss how a specific "Submit" button only enables when three disparate fields meet a specific regex.

Legacy Logic (Pseudocode):

javascript
// Found in a 2000-line script.js file with no comments
function validateForm() {
    var status = document.getElementById('user_status').value;
    var age = parseInt(document.getElementById('age_input').value);
    if (status === 'active' && age > 18 || user_override === true) {
        document.getElementById('submit_btn').disabled = false;
    }
}

Replay Extracted React Component: Replay identifies this interaction during the recording and generates a clean, type-safe React component that encapsulates this logic within a custom hook or state manager.

typescript
import React, { useState, useEffect } from 'react';

interface ValidationProps {
  userStatus: string;
  age: number;
  hasOverride: boolean;
}

export const ModernizedSubmitButton: React.FC<ValidationProps> = ({ 
  userStatus, 
  age, 
  hasOverride 
}) => {
  const [isDisabled, setIsDisabled] = useState(true);

  useEffect(() => {
    // Logic reconciled from runtime observation
    const isValid = (userStatus === 'active' && age > 18) || hasOverride;
    setIsDisabled(!isValid);
  }, [userStatus, age, hasOverride]);

  return (
    <button 
      disabled={isDisabled}
      className="btn-primary"
      onClick={() => console.log('Form Submitted')}
    >
      Submit Application
    </button>
  );
};

The 3-Step Framework for Logic Reconciliation Audits Comparing Visual State to Code#

To execute a successful audit, enterprise architects should follow a structured approach that prioritizes high-impact workflows.

1. Workflow Recording and Capture#

The process begins by recording real users performing their daily tasks in the legacy system. This isn't just a screen recording; it's a data capture. Tools like Replay capture the DOM mutations, network requests, and state changes occurring under the hood.

2. Discrepancy Identification#

Once the runtime is captured, it is compared against the "Golden Source" documentation. This is where logic reconciliation audits comparing the two datasets happen. If the documentation says the system uses a 5-step approval process, but the runtime recording shows a 7-step process with a hidden manager override, you have identified a critical logic gap.

3. Automated Blueprint Generation#

Instead of writing a new spec, Replay uses its AI Automation Suite to generate "Blueprints." These are intermediate representations of the UI and logic that can be reviewed by architects before being converted into a Design System.

Why 70% of Legacy Rewrites Fail#

The statistic is haunting: 70% of legacy rewrites fail or significantly exceed their timelines. The primary reason is "Scope Creep via Discovery." When you don't perform logic reconciliation audits comparing the runtime to the docs at the start of the project, you discover the "Ghost Logic" during the coding phase.

This leads to:

• •Refactoring loops: Realizing the new architecture can't support an undocumented but vital business rule.
• •Budget overruns: Spending 40 hours per screen to manually reverse engineer logic that could have been captured in minutes.
• •Stakeholder friction: Delivering a "modern" system that lacks the nuanced functionality of the 20-year-old system it replaced.

By using Replay, organizations move from an 18-24 month timeline down to weeks or months. You are not starting from a blank page; you are starting from a documented, validated representation of your existing business value.

Implementation Details: From Recording to Component Library#

For a Senior Enterprise Architect, the value of Replay lies in its ability to output structured, production-ready code. Let's look at how a recorded flow is converted into a documented component library.

Step 1: The Recording A user records a complex data grid in a legacy insurance underwriting tool. The grid has complex conditional formatting and inline editing.

Step 2: The Logic Extraction Replay's engine analyzes the recording. It identifies that the "Premium" column changes color based on a combination of "Risk Score" and "Coverage Type."

Step 3: The Output Replay generates a React component using a modern library like Tailwind CSS or Material UI, complete with the reconciled logic.

typescript
// Replay Generated: UnderwritingGrid.tsx
import { useMemo } from 'react';

interface RowData {
  riskScore: number;
  coverageType: 'Full' | 'Partial' | 'Basic';
  premium: number;
}

const getPremiumColor = (score: number, type: string): string => {
  // Logic reconciled from visual runtime observation
  if (type === 'Full' && score > 80) return 'text-red-600 font-bold';
  if (score < 30) return 'text-green-600';
  return 'text-gray-900';
};

export const UnderwritingGrid = ({ data }: { data: RowData[] }) => {
  return (
    <table className="min-w-full divide-y divide-gray-200">
      <thead>
        <tr>
          <th>Risk Score</th>
          <th>Coverage</th>
          <th>Premium</th>
        </tr>
      </thead>
      <tbody>
        {data.map((row, idx) => (
          <tr key={idx}>
            <td>{row.riskScore}</td>
            <td>{row.coverageType}</td>
            <td className={getPremiumColor(row.riskScore, row.coverageType)}>
              ${row.premium.toLocaleString()}
            </td>
          </tr>
        ))}
      </tbody>
    </table>
  );
};

Security and Compliance in Regulated Environments#

For industries like Financial Services, Healthcare, and Government, logic reconciliation isn't just about efficiency—it's about compliance. You must prove that the new system handles data with the same integrity as the old one.

Replay is built for these environments. With SOC2 compliance and HIPAA-ready protocols, it can be deployed on-premise to ensure that sensitive data captured during the recording phase never leaves your secure perimeter. This allows for logic reconciliation audits comparing sensitive runtimes without violating data sovereignty laws.

The Role of AI in Logic Reconciliation#

While Replay uses advanced heuristics to extract components, its AI Automation Suite provides the "narrative" layer. It explains why a certain component was built the way it was, linking the generated code back to the visual recording. This creates a living documentation trail that stays updated as the modernization progresses.

Conclusion: Stop Guessing, Start Recording#

The era of manual requirements gathering for legacy systems is over. The risks are too high, and the costs are too great. By implementing logic reconciliation audits comparing your visual runtimes to your existing documentation, you gain a clear, data-driven roadmap for modernization.

Replay offers a path out of technical debt by turning the "black box" of legacy UIs into a transparent library of React components and documented flows. Whether you are dealing with a $3.6 trillion debt or a single mission-critical application, the methodology remains the same: capture the truth of the runtime, reconcile the logic, and automate the transition.

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Frequently Asked Questions#

What is the primary benefit of logic reconciliation audits comparing runtimes to documentation?#

The primary benefit is identifying "Ghost Logic"—business rules that exist in the production environment but are missing from official documentation. This prevents critical functional gaps in the modernized application and reduces the risk of project failure.

How does Replay handle complex state transitions during an audit?#

Replay's Visual Reverse Engineering engine monitors DOM mutations and network requests in real-time during a recording. It maps these changes to a state machine, which is then used to generate React hooks and components that accurately mirror the legacy system's behavior.

Is logic reconciliation suitable for highly regulated industries like Healthcare?#

Yes. In fact, it is often a requirement. Replay is SOC2 and HIPAA-ready, offering on-premise deployment options to ensure that the reconciliation process meets strict data privacy and security standards while providing a clear audit trail of the modernization.

Can Replay generate a full design system from a legacy recording?#

Absolutely. Replay’s Library feature extracts visual tokens (colors, typography, spacing) and component structures from the recording to build a unified Design System. This ensures visual consistency across the new application suite.

How much time can I save using Replay for logic reconciliation?#

On average, Replay reduces the time spent on manual screen analysis and documentation from 40 hours per screen to just 4 hours. This represents a 70-90% time saving, allowing enterprise projects to move from years to weeks.

Ready to modernize without rewriting? Book a pilot with Replay