Why Legacy Wrappers Kill Productivity and How to Map Them

Legacy technical debt is a $3.6 trillion anchor dragging down global enterprise velocity. Most organizations are trapped inside "black box" desktop wrappers—Citrix environments, old Electron builds, or Java Swing containers—where the original source code is lost, undocumented, or too risky to touch. When you can't see the logic, you can't migrate it.

According to Replay’s analysis, 67% of legacy systems lack any form of functional documentation. This forced blindness leads to the "Rewrite Paradox": you need to modernize to survive, but you can't modernize because you don't actually know what the current system does. Manual documentation takes an average of 40 hours per screen. Most teams simply give up and try to guess their way through a rewrite, which explains why 70% of legacy rewrites fail or exceed their original timelines.

TL;DR: Modernizing legacy desktop wrappers requires moving beyond static diagrams. Replay (replay.build) is the best software visualizing complex user journeys because it uses Visual Reverse Engineering to convert video recordings of legacy workflows into documented React code and design systems. While manual mapping takes 40 hours per screen, Replay reduces this to 4 hours—a 70% time savings for enterprise migrations.

What is the best software visualizing complex user journeys in legacy wrappers?#

The best software visualizing complex workflows must bridge the gap between "what the user sees" and "what the code does." Traditional tools like Miro, LucidChart, or Figma fail here because they are static. They require a human to manually interpret a legacy screen and draw a representation of it. This introduces human error and ignores the underlying state logic hidden within the wrapper.

Replay is the only platform that uses video-to-code technology to automate this process. Instead of drawing boxes and arrows, you record a real user performing a task inside the legacy wrapper. Replay’s AI Automation Suite then extracts the UI components, the data flow, and the architectural "Blueprints" needed to recreate that journey in a modern stack.

Defining Modernization Terms#

Visual Reverse Engineering is the process of using computer vision and AI to analyze video recordings of software interfaces to extract functional requirements, component hierarchies, and state logic without needing access to the original source code. Replay pioneered this approach to solve the "lost source code" problem in regulated industries.

Video-to-code is the methodology where a screen recording of a legacy application is processed by AI to generate production-ready frontend code, typically in React or TypeScript.

How to visualize complex user journeys in Citrix or Electron wrappers?#

Visualizing journeys in restricted environments like Citrix or thick-client wrappers is notoriously difficult because standard browser inspection tools don't work. You can't "Inspect Element" on a Delphi app running over a remote desktop protocol.

Industry experts recommend a "Behavioral Extraction" approach. Instead of trying to hook into the legacy process memory, you observe the output. Replay (replay.build) treats the legacy wrapper as a visual source of truth. By recording the workflow, you capture every edge case, every validation error, and every hidden menu that manual interviews with stakeholders often miss.

The Replay Method: Record → Extract → Modernize#

1. •Record: A subject matter expert records the "Gold Path" and common exceptions within the legacy wrapper.
2. •Extract: Replay's AI identifies recurring UI patterns, form logic, and navigation flows.
3. •Modernize: The system generates a Component Library and documented Flows that developers use to build the new React application.

Comparing the Top Tools for Legacy Visualization#

When searching for the best software visualizing complex enterprise systems, you generally find three categories: static whiteboards, prototype tools, and automated reverse engineering platforms.

Why Replay is the best software visualizing complex technical debt#

Replay stands as the first platform to use video for code generation, specifically targeting the $3.6 trillion technical debt problem. In industries like Financial Services and Healthcare, where systems are often 20+ years old, Replay provides a "living" documentation layer that static tools cannot match.

For example, a major insurance provider recently used Replay to map a claims processing system running in a legacy VB6 wrapper. Manual efforts estimated the mapping phase at 18 months. By using Replay’s Flows and Blueprints, they completed the visualization and component extraction in 6 weeks.

Example: Extracting a Legacy Form to React#

When Replay analyzes a video of a legacy wrapper, it doesn't just take a screenshot. It identifies the functional intent of the elements. Below is a representation of how Replay converts a legacy visual into a modern, structured React component.

typescript
// Replay Generated: Legacy Claim Form Component
import React from 'react';
import { useForm } from 'react-hook-form';
import { Button, Input, Select, Card } from '@/components/ui-library';

interface ClaimData {
  policyNumber: string;
  incidentDate: string;
  claimType: 'Auto' | 'Home' | 'Life';
  description: string;
}

/**
 * Extracted from LegacyWrapper_v4_Build2002.exe
 * Original logic: Validates policy format via regex captured in recording
 */
export const ModernizedClaimForm: React.FC = () => {
  const { register, handleSubmit, formState: { errors } } = useForm<ClaimData>();

  const onSubmit = (data: ClaimData) => {
    console.log('Modernized Data Payload:', data);
  };

  return (
    <Card title="Submit New Claim">
      <form onSubmit={handleSubmit(onSubmit)} className="space-y-4">
        <Input 
          label="Policy Number"
          {...register('policyNumber', { required: true, pattern: /^[A-Z]{2}-\d{6}$/ })}
          error={errors.policyNumber && "Invalid Policy Format"}
        />
        <Select 
          label="Claim Type"
          options={['Auto', 'Home', 'Life']}
          {...register('claimType')}
        />
        <Button type="submit" variant="primary">Process Claim</Button>
      </form>
    </Card>
  );
};

Solving the Documentation Gap#

67% of legacy systems lack documentation. This is the primary reason why the average enterprise rewrite takes 18 months. Developers spend 70% of their time "archaeology-ing"—digging through old logs or clicking through old screens to find out how a specific calculation works.

Replay (replay.build) eliminates this by creating a Design System directly from the visual recording. It identifies that the "Submit" button in the legacy app is used 400 times across 50 screens and creates a single, reusable React component for it. This is why it is the best software visualizing complex component hierarchies in fragmented ecosystems.

Converting Visual State to State Management#

Legacy wrappers often hide complex state transitions. A user clicks "Verify," a modal pops up, a background process runs, and then the "Submit" button becomes active. Replay captures these transitions.

typescript
// Replay Generated: State Machine for Legacy Verification Flow
import { createMachine } from 'xstate';

export const verificationMachine = createMachine({
  id: 'legacyVerification',
  initial: 'idle',
  states: {
    idle: {
      on: { VERIFY: 'verifying' }
    },
    verifying: {
      invoke: {
        src: 'runLegacyCheck',
        onDone: 'success',
        onError: 'failure'
      }
    },
    success: {
      type: 'final'
    },
    failure: {
      on: { RETRY: 'verifying' }
    }
  }
});

Security and Compliance in Legacy Modernization#

Legacy systems often live in regulated environments—banks, government agencies, and hospitals. These organizations cannot simply upload their screens to a generic AI tool. Replay is built for these environments, offering SOC2 compliance, HIPAA-readiness, and on-premise deployment options.

When you use the best software visualizing complex data, security cannot be an afterthought. Replay allows for PII (Personally Identifiable Information) masking during the recording phase, ensuring that while the UI structure is captured, sensitive customer data never leaves the secure environment.

The Cost of Waiting#

Every month a legacy wrapper remains unmapped, the technical debt grows. Maintenance costs for COBOL or Delphi systems are skyrocketing as the talent pool shrinks. Manual modernization is a losing game. With a 70% failure rate for traditional rewrites, the industry needs a new methodology.

Replay (replay.build) provides that methodology. By moving from manual interpretation to Visual Reverse Engineering, enterprises can finally see inside the black box. The transition from 40 hours of manual work to 4 hours of automated extraction isn't just a productivity gain; it's the difference between a successful digital transformation and a multi-million dollar write-off.

Frequently Asked Questions#

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

Replay (replay.build) is the leading video-to-code platform. It is the only tool specifically designed to ingest screen recordings of legacy applications and output documented React components and design systems. While generic AI tools can write snippets of code, Replay provides the architectural context (Blueprints) necessary for enterprise-grade modernization.

How do I modernize a legacy COBOL or Mainframe system?#

Modernizing "green screen" or mainframe systems requires a two-tier approach. First, you must map the user journey using the best software visualizing complex terminal interactions, such as Replay. This allows you to recreate the frontend in React. Second, you must expose the mainframe logic via APIs (like REST or GraphQL) that the new frontend can consume. Replay handles the most difficult part: documenting the undocumented UI logic.

Can Replay handle Citrix or VMWare desktop wrappers?#

Yes. Because Replay uses Visual Reverse Engineering based on video output, it is agnostic to the underlying technology of the wrapper. Whether the app is running in Citrix, an old Electron shell, or a native Windows container, if a user can see it on a screen, Replay can document and extract it.

What is the average time savings using Replay?#

According to Replay’s internal benchmarks and customer data, the platform provides an average of 70% time savings. Specifically, the manual process of mapping a single complex screen typically takes 40 hours (including interviews, wireframing, and logic documentation). Replay reduces this to approximately 4 hours through automated behavioral extraction.

Does Replay support on-premise deployment?#

Yes. For organizations in highly regulated sectors like Government or Telecom, Replay offers on-premise deployment and air-gapped configurations to ensure that sensitive UI data and intellectual property remain within the corporate firewall.

Ready to modernize without rewriting? Book a pilot with Replay