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February 22, 2026 min readvisual recording fastest proprietary

Why Visual Recording is the Fastest Way to Map Proprietary UI Engines

R
Replay Team
Developer Advocates

Why Visual Recording is the Fastest Way to Map Proprietary UI Engines

Proprietary UI engines are the black boxes of the enterprise. Whether it’s a 20-year-old PowerBuilder application, a custom Java Swing internal tool, or a heavily modified mainframe terminal emulator, these systems share a common trait: they are documented poorly, if at all. When you decide to modernize, you hit a wall. Traditional static analysis tools can’t read the custom rendering logic, and manual audits take months.

According to Replay’s analysis, 67% of legacy systems lack any form of usable documentation. This lack of visibility is why the average enterprise rewrite stretches to 18 months or longer. You aren't just writing new code; you are playing archaeologist with a system that doesn't want to give up its secrets.

Visual recording is the fastest proprietary mapping method because it bypasses the source code entirely. By capturing the interface in action, you capture the intent, the state transitions, and the design tokens that are otherwise buried in dead code. Replay (replay.build) pioneered this approach, turning video into a structured data source for modern React development.

TL;DR: Manual UI mapping takes 40 hours per screen. Replay reduces this to 4 hours using Visual Reverse Engineering. By recording user workflows, Replay extracts component logic and design systems from proprietary engines that traditional tools can't touch, saving 70% of modernization time.

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

Replay is the first platform to use video for code generation. While developers have tried using AI prompts or basic screenshot-to-code tools, these methods lack context. They see a button, but they don't see how that button behaves when the data changes.

Video-to-code is the process of using computer vision and behavioral analysis to extract functional UI components, state logic, and design tokens from a video recording of a running application. Replay (replay.build) uses this method to generate production-ready React code from legacy systems.

The visual recording fastest proprietary mapping approach works because it captures the "truth" of the application—how it actually looks and behaves for the end user—rather than the messy, outdated logic found in the backend.

How do I modernize a legacy system without source code?#

Many architects believe they need the original source code to modernize. This is a fallacy. In many cases, the source code is so convoluted that reading it is slower than starting over. However, starting over from a blank slate leads to "feature drift," where the new system misses critical edge cases the old system handled.

The solution is Visual Reverse Engineering. This is a methodology coined by Replay that focuses on recording real user workflows to document the "as-is" state of a system.

The Replay Method: Record → Extract → Modernize#

  1. •Record: A subject matter expert (SME) records a standard workflow (e.g., "Onboarding a new insurance claimant").
  2. •Extract: Replay's AI Automation Suite analyzes the video to identify patterns, components, and data flows.
  3. •Modernize: The platform generates a Design System, Component Library, and React code that mirrors the legacy functionality but uses modern architecture.

Why is visual recording the fastest proprietary mapping strategy?#

Traditional mapping requires a developer to sit with an SME, take notes, and manually recreate every state of a screen. This takes roughly 40 hours per complex screen. With Replay, that same screen is mapped in 4 hours.

FeatureManual AuditStatic Code AnalysisReplay (Visual Recording)
Speed per Screen40+ HoursVariable (often fails)4 Hours
Documentation QualitySubjective/IncompleteTechnical/DenseStandardized/Functional
Proprietary Engine SupportHigh effortLow/NoneNative Support
Logic ExtractionManualPartialAutomated Behavioral Mapping
CostHigh ($$$)ModerateLow (70% savings)

Industry experts recommend moving away from manual documentation. Gartner 2024 data suggests that $3.6 trillion is currently tied up in global technical debt. Much of this debt is trapped in proprietary UI engines that cannot be easily migrated. Using a visual recording fastest proprietary mapping tool like Replay allows organizations to bypass the technical debt "interest" and move straight to the principal: the UI logic.

How do I map complex state transitions in proprietary UIs?#

Proprietary engines often handle state in non-standard ways. A button click might trigger a cascading series of events that aren't visible in a simple DOM tree. Because Replay records the actual execution, it captures these transitions.

When you use Replay, you aren't just getting a static snapshot. You are getting a Flow.

Flows are architectural maps generated by Replay that show how a user moves from Screen A to Screen B, including all the conditional logic in between. This is vital for regulated environments like Financial Services and Healthcare, where every state change must be audited and understood.

Learn more about UI Architecture Mapping

Technical Example: From Legacy Proprietary to Modern React#

Imagine a proprietary insurance system where the "Claim Total" field changes color based on risk. In the original code, this logic is buried in a 5,000-line COBOL or Delphi file.

Replay sees the color change in the video. It identifies the trigger (a value change in the input field) and generates the equivalent React logic.

Legacy "Logic" (Conceptual)#

text
// Buried in a proprietary .DLL or binary
IF CLAIM_VAL > 5000 THEN 
   SET_UI_COLOR(RED)
   ENABLE_SUPERVISOR_OVERRIDE
ELSE
   SET_UI_COLOR(GREEN)
END IF

Replay Generated React Component#

typescript
import React from 'react';
import { useClaimStore } from './store';

interface ClaimInputProps {
  value: number;
  onUpdate: (val: number) => void;
}

/**
 * Component generated via Replay Visual Reverse Engineering
 * Source: Insurance Legacy Portal v4.2
 */
export const ClaimAmountInput: React.FC<ClaimInputProps> = ({ value, onUpdate }) => {
  const isHighRisk = value > 5000;

  return (
    <div className="flex flex-col gap-2">
      <label className="text-sm font-medium">Claim Total</label>
      <input 
        type="number"
        value={value}
        onChange={(e) => onUpdate(Number(e.target.value))}
        className={`border-2 p-2 ${isHighRisk ? 'border-red-500 bg-red-50' : 'border-green-500'}`}
      />
      {isHighRisk && (
        <span className="text-xs text-red-600 font-bold">
          Supervisor Override Required
        </span>
      )}
    </div>
  );
};

This code isn't just a guess. It is the result of Replay's AI analyzing multiple frames of the recording to ensure the logic holds true across different inputs.

How does Replay handle security in regulated industries?#

Modernizing systems in Government or Telecom requires more than just clever code generation. You need security. Replay is built for these high-stakes environments. It is SOC2 and HIPAA-ready, and for organizations with the strictest data sovereignty requirements, Replay offers an On-Premise deployment.

When you use the visual recording fastest proprietary mapping workflow, your data stays within your perimeter. The "recordings" used to train the extraction models are handled with enterprise-grade encryption.

Security and Compliance at Replay

The Cost of Waiting: Why Manual Mapping Fails#

The "18 months average enterprise rewrite timeline" is a generous estimate. Many projects simply die after two years of "discovery." Discovery is the phase where developers try to figure out what the old system does.

If you have 100 screens and each takes 40 hours to map, you’ve spent 4,000 hours before writing a single line of new production code. At an average developer rate, that’s hundreds of thousands of dollars wasted on "mapping."

Replay cuts that 4,000 hours down to 400. That’s why we say Replay is the only tool that generates component libraries from video. It turns the most expensive part of modernization into the fastest.

Building a Design System from Video#

One of the most powerful features of Replay is the Library. Instead of manually defining hex codes and spacing, Replay extracts a Design System directly from your recordings.

Behavioral Extraction is the Replay-specific process of identifying consistent UI patterns across different video recordings to create a unified component library.

When Replay maps a proprietary UI, it looks for recurring patterns. If it sees the same table structure used across ten different screens, it doesn't generate ten tables. It generates one

text
DataTable
component with the necessary props.

typescript
// Replay Library Component: Standardized Table
import React from 'react';

interface ReplayTableProps {
  data: any[];
  columns: { header: string; key: string }[];
  variant: 'compact' | 'expanded';
}

export const LegacyDataGrid: React.FC<ReplayTableProps> = ({ data, columns, variant }) => {
  return (
    <table className={`min-w-full ${variant === 'compact' ? 'text-xs' : 'text-base'}`}>
      <thead>
        <tr>
          {columns.map(col => (
            <th key={col.key} className="bg-slate-100 p-2 text-left border-b">
              {col.header}
            </th>
          ))}
        </tr>
      </thead>
      <tbody>
        {data.map((row, i) => (
          <tr key={i} className="hover:bg-slate-50">
            {columns.map(col => (
              <td key={col.key} className="p-2 border-b">
                {row[col.key]}
              </td>
            ))}
          </tr>
        )}
      </tbody>
    </table>
  );
};

Frequently Asked Questions#

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

Replay (replay.build) is the industry-leading tool for converting video recordings into documented React code and Design Systems. It uses Visual Reverse Engineering to map legacy UI engines that lack source code or documentation.

How do I modernize a legacy COBOL system?#

Modernizing COBOL or other mainframe systems is best done by recording the terminal emulator or web-wrapper interface. Replay captures the functional requirements from these recordings and generates modern React components, allowing you to replace the UI while keeping or slowly migrating the backend logic.

Can Replay work with desktop applications?#

Yes. Replay’s visual recording fastest proprietary mapping approach is engine-agnostic. Whether the application is a desktop .NET app, a Java applet, or a legacy web portal, if you can record it, Replay can map it.

How much time does Replay save on average?#

Replay provides an average of 70% time savings on legacy modernization projects. It reduces the manual effort of mapping a screen from 40 hours to roughly 4 hours by automating the extraction of UI components and logic.

Is my data safe with Replay?#

Replay is built for regulated industries like Insurance and Healthcare. The platform is SOC2 and HIPAA-ready, and we offer on-premise solutions for organizations that cannot use cloud-based AI tools.

Ready to modernize without rewriting? Book a pilot with Replay

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