The Archaeology of Business Logic: Why Video Records Are More Accurate Than Source Code

Your source code is a graveyard of intentions, not a map of reality. In the enterprise, we’ve been taught that the "source of truth" lives in the repository. But for systems that have survived three decades of acquisitions, developer turnover, and emergency hotfixes, the code is often a deceptive layer of sediment.

The industry is currently buried under a $3.6 trillion mountain of technical debt. When we attempt to modernize these systems, we don’t act like engineers; we act like archaeologists. We dig through layers of dead code, commented-out logic, and "temporary" patches from 2008, hoping to find the actual business rules that govern the organization.

The problem is that 67% of legacy systems lack any meaningful documentation. When you look at a 5,000-line Java controller, you aren't seeing what the system does—you’re seeing every version of what it might have done over the last twenty years.

TL;DR: Visual Reverse Engineering through tools like Replay allows architects to bypass the "archaeology" of dead source code by using recorded user workflows as the definitive source of truth for modernizing legacy systems.

The Archaeology of Business Logic: Why Code Lies#

In a perfect world, the code is the documentation. In the enterprise world, the code is a crime scene. We call it The Archaeology of Business Logic because the process of modernizing a legacy system usually involves unearthing "artifacts" that no longer serve a purpose but cannot be removed because no one knows why they were put there in the first place.

Traditional modernization fails because it starts with the "How" (the code) rather than the "What" (the behavior).

The Documentation Gap#

When 70% of legacy rewrites fail or exceed their timelines, the culprit is almost always "hidden logic." These are the edge cases that aren't in the requirements doc and aren't obvious in the spaghetti code, but are critical to the business.

Manual reverse engineering—where an architect sits with a developer to trace a single transaction through 15 microservices—takes an average of 40 hours per screen. This "archaeology" is the single greatest bottleneck in the enterprise.

Moving From "Archaeology" to "Observation"#

The future of modernization isn't rewriting from scratch; it's understanding what you already have by observing it in motion. If the source code is a static map of a city that has been rebuilt ten times, a video recording of a user workflow is a GPS trace of how people actually navigate the streets.

By recording a real user workflow, Replay captures the "living" business logic. It ignores the dead code paths that never execute and focuses on the exact API calls, data transformations, and UI states that occur during a successful transaction.

💡 Pro Tip: Don't start your modernization project by reading the code. Start by recording the top 20 workflows that generate 80% of your business value. This defines your "Minimum Viable Migration."

Turning Video into React Components#

One of the most significant advantages of visual reverse engineering is the ability to generate modern equivalents of legacy UI instantly. Instead of a developer spending a week trying to replicate a complex insurance claim form in React, Replay extracts the DOM structure, state logic, and styling from the recording.

typescript
// Example: Replay-generated component from a legacy JSP extraction
// The logic is preserved based on observed runtime behavior, not static code analysis.

import React, { useState, useEffect } from 'react';
import { ModernButton, LegacyInput, ValidationWrapper } from '@enterprise-ds/core';

export function ClaimsAdjustmentForm({ initialData }) {
  const [claimState, setClaimState] = useState(initialData);
  const [isEligible, setIsEligible] = useState(false);

  // Business logic extracted from observed "Flows" in Replay
  const validateEligibility = (data: any) => {
    // Replay identified this specific conditional logic during the recording
    return data.policyType === 'PREMIUM' && data.claimAmount < 50000;
  };

  return (
    <ValidationWrapper>
      <LegacyInput 
        value={claimState.amount} 
        onChange={(e) => setClaimState({...claimState, amount: e.target.value})}
      />
      {validateEligibility(claimState) && (
        <ModernButton onClick={() => submitClaim(claimState)}>
          Auto-Approve Claim
        </ModernButton>
      )}
    </ValidationWrapper>
  );
}

The Replay Framework: Modernizing Without the Archaeology#

Replay transforms the modernization process from a 24-month "Big Bang" risk into a predictable, automated pipeline. It targets the core pain points of the Enterprise Architect: technical debt, documentation gaps, and budget overruns.

1. The Library (Design System)#

Most legacy systems have inconsistent UI. Replay’s Library feature identifies recurring patterns across your recorded workflows and maps them to a unified Design System. This ensures that your modernized application isn't just new code, but a cohesive user experience.

2. Flows (Architecture Mapping)#

"Flows" are the visual representation of your business logic. By recording a workflow, Replay automatically generates:

• •API Contracts: See exactly what the frontend sends to the backend.
• •E2E Tests: Automatically generated Playwright or Cypress tests based on the recording.
• •Sequence Diagrams: Visualizing how data moves through your system.

3. Blueprints (The Editor)#

The Blueprint editor allows architects to tweak the extracted logic before it’s committed to the new codebase. This is where you bridge the gap between "what the legacy system did" and "what the modern system should do."

💰 ROI Insight: Manual screen reconstruction takes ~40 hours per screen for a senior developer. Replay reduces this to ~4 hours. In an enterprise application with 200 screens, that is a savings of 7,200 engineering hours—roughly $1.1M in labor costs alone.

Step-by-Step: The Visual Reverse Engineering Workflow#

To move from a black box to a documented codebase, we follow a structured extraction process.

Step 1: Workflow Identification#

Identify the critical business paths. In Financial Services, this might be "Open New Account" or "Process Wire Transfer." In Healthcare, it’s "Patient Intake" or "Claims Submission."

Step 2: Recording the Truth#

A subject matter expert (SME) performs the task while Replay records the session. Unlike a simple screen recording, Replay captures the underlying metadata: network requests, state changes, and DOM mutations.

Step 3: Automated Extraction#

Replay’s AI Automation Suite parses the recording. It identifies the components used, the data validation rules applied, and the external services called.

Step 4: Refinement and Export#

The Architect reviews the generated "Blueprint." Once validated, Replay exports production-ready React components, TypeScript interfaces, and comprehensive documentation.

⚠️ Warning: Do not attempt to automate the extraction of 100% of your legacy system. Focus on the 20% of code that handles 80% of the transactions. Use the "Strangler Fig" pattern to migrate these high-value flows first.

Addressing the "Black Box" Concern#

A common objection from VPs of Engineering is: "If we use a tool to extract the logic, do we actually understand the new system?"

The answer is that you understand it better. Traditional rewrites involve developers making "best guesses" about legacy code they didn't write. This leads to the "Bug-for-Bug Compatibility" trap, where you accidentally replicate 20-year-old bugs in a modern framework.

Replay provides a Technical Debt Audit as part of the extraction. It highlights logic that appears redundant or inconsistent across different workflows, allowing you to clean the "archaeological site" as you build the new structure.

Frequently Asked Questions#

How long does legacy extraction take?#

While a traditional enterprise rewrite takes 18-24 months, a Replay-driven modernization typically delivers the first production-ready modules in 2-8 weeks. The time savings come from eliminating the "discovery phase" where developers struggle to understand the legacy source code.

What about business logic preservation?#

Replay captures the behavioral truth. If a legacy system requires a specific, obscure sequence of API calls to process a transaction, Replay records that sequence exactly. This "video as source of truth" ensures that no edge cases are lost in translation.

Can Replay work in highly regulated environments?#

Yes. Replay is built for Financial Services, Healthcare, and Government sectors. We offer on-premise deployments to ensure that sensitive data never leaves your network, and the platform is SOC2 and HIPAA-ready.

Does it support non-web legacy systems?#

Replay is optimized for web-based legacy systems (Java/Spring, .NET, PHP, Delphi web wrappers). For "green screen" or thick-client terminal systems, we provide specialized adapters that map terminal outputs to modern web components.

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