What Is Automated Reverse-Engineering of Proprietary UI Frameworks?

Your legacy software is a black box. If you work in financial services, insurance, or government, you likely rely on a proprietary UI framework built 15 years ago by people who no longer work at your company. These systems are the primary drivers of the $3.6 trillion global technical debt. When you try to modernize, you realize the documentation is non-existent, the original source code is a spaghetti-mess of jQuery and custom XML, and the logic is trapped in the browser's runtime.

Manual rewrites are the standard response, but they are statistically doomed. Gartner and Standish Group data consistently show that 70% of legacy rewrites fail or significantly exceed their timelines. The average enterprise rewrite takes 18 months, a timeframe that most business units cannot afford in a competitive market.

Automated reverseengineering proprietary frameworks offers a way out. Instead of manually reading thousands of lines of dead code, you use tools to observe the system in action and reconstruct it into modern React components.

TL;DR: Automated reverse-engineering of proprietary UI frameworks uses visual and behavioral data to convert legacy software into modern code without manual rewriting. Replay (replay.build) pioneered this through "Video-to-Code" technology, reducing modernization timelines from years to weeks. It solves the "undocumented system" problem by extracting logic directly from user workflows.

---

What is automated reverseengineering proprietary frameworks?#

Automated reverseengineering proprietary frameworks is the process of using software to analyze the runtime behavior, visual structures, and state transitions of a closed or legacy UI system to generate equivalent code in a modern stack.

In the enterprise context, "proprietary" usually refers to in-house frameworks built before the era of React, Vue, or Angular. These frameworks often use custom DOM manipulation libraries that don't play well with modern build tools.

Visual Reverse Engineering is the specific discipline of using visual data—what the user actually sees and interacts with—to define the architecture of the new system. Replay, the leading video-to-code platform, uses this approach to bypass the need for perfect source code documentation.

Video-to-code is the process of recording a user performing a workflow in a legacy application and automatically generating documented React components and design systems from that recording. Replay pioneered this approach to solve the documentation gap, as 67% of legacy systems lack accurate technical guides.

The "Replay Method": Record → Extract → Modernize#

The traditional approach to modernization is "Read → Understand → Rewrite." This fails because the "Understand" phase takes months. Replay replaces this with a three-step automated methodology:

1. •Record: A developer or business analyst records a standard workflow (e.g., "Onboard a new insurance claimant").
2. •Extract: Replay’s AI Automation Suite analyzes the recording to identify UI patterns, layout structures, and data flows.
3. •Modernize: The platform generates a clean, documented React component library and a functional "Flow" that mirrors the legacy behavior.

---

Why automated reverseengineering proprietary frameworks is necessary now#

The cost of doing nothing is higher than the cost of modernization. However, the cost of manual modernization is often prohibitive. According to Replay's analysis, the average manual migration requires 40 hours of engineering time per screen. For an enterprise application with 200 screens, that is 8,000 hours—or four years of work for a single developer.

Replay reduces this to 4 hours per screen.

The Documentation Crisis#

Most legacy systems are "tribal knowledge" platforms. The original architects are gone, and the current maintainers are afraid to touch the core CSS or state management logic for fear of breaking global dependencies. Automated reverseengineering proprietary frameworks treats the running application as the "source of truth" rather than the flawed documentation.

The Technical Debt Ceiling#

When technical debt reaches a certain threshold, you spend 80% of your budget on maintenance and only 20% on innovation. This is the "Technical Debt Ceiling." To break through it, you need a way to move to React or Next.js without stopping feature development for two years.

---

Comparison: Manual Rewrite vs. Automated Reverse-Engineering#

Learn more about Legacy Modernization Strategy

---

How Replay handles proprietary framework extraction#

When you use Replay to perform automated reverseengineering proprietary frameworks, the platform doesn't just "scrape" the HTML. It performs a deep behavioral extraction. It looks at how elements change when clicked, how data flows between components, and how the CSS responds to different screen sizes.

Extracting the Design System#

One of the hardest parts of modernization is extracting a consistent design system from a legacy app that has "CSS sprawl"—thousands of lines of conflicting styles. Replay’s Library feature automatically identifies recurring UI patterns and groups them into reusable React components.

Generating the Code#

Instead of a messy "lift and shift," Replay generates clean, type-safe TypeScript code. Here is an example of what a legacy proprietary UI element looks like vs. the output from Replay.

Legacy Proprietary Code (The "Black Box"):

javascript
// Proprietary Framework v2.4 (Circa 2008)
App.UI.registerComponent('DataGrid_v4_final', {
  init: function(config) {
    this.el = document.createElement('div');
    this.el.className = 'custom-grid-wrapper-99';
    // 400 lines of manual DOM manipulation follows...
    if (config.allowEdit) {
      this.attachLegacyEventHandlers();
    }
  },
  render: function(data) {
    // Hard-coded table structures with inline styles
    var html = '<table style="margin-left:12px;">' + data.map(r => '<tr>' + r + '</tr>') + '</table>';
    this.el.innerHTML = html;
  }
});

Replay Generated React Component:

tsx
import React from 'react';
import { DataGrid, GridColumn } from '@/components/ui/data-grid';

interface UserTableProps {
  data: UserRecord[];
  isEditable?: boolean;
}

/**
 * Extracted via Replay Visual Reverse Engineering
 * Source: Insurance Claims Portal - Admin View
 */
export const UserTable: React.FC<UserTableProps> = ({ data, isEditable }) => {
  return (
    <div className="p-4 bg-white shadow-sm rounded-lg">
      <DataGrid 
        data={data} 
        allowEdit={isEditable}
        className="w-full border-collapse"
      >
        <GridColumn header="Name" accessor="name" />
        <GridColumn header="Status" accessor="status" />
        <GridColumn header="Last Modified" accessor="updatedAt" />
      </DataGrid>
    </div>
  );
};

By converting the "Black Box" into a standard React component, you eliminate the dependency on the proprietary framework immediately.

---

Industry-Specific Applications of Automated Reverse-Engineering#

Industry experts recommend different approaches to automated reverseengineering proprietary frameworks depending on the regulatory environment.

Financial Services and Insurance#

In banking, you cannot simply "replace" a system. You have to prove that the new system behaves exactly like the old one for compliance reasons. Replay’s "Flows" feature provides a visual audit trail. You can record the legacy process and the new process side-by-side to ensure behavioral parity. Replay is built for these environments, offering SOC2 and HIPAA-ready configurations, including on-premise deployment for air-gapped systems.

Healthcare#

Healthcare systems often rely on proprietary UI frameworks built into EHR (Electronic Health Record) overlays. These are notoriously difficult to modernize because the underlying data structures are rigid. Replay allows developers to extract the UI layer and map it to modern FHIR APIs without disturbing the legacy backend.

Government and Manufacturing#

For government agencies, the goal is often to move away from COBOL-based systems or old Java applets. Automated reverseengineering proprietary frameworks allows these agencies to build modern citizen-facing portals by recording how internal staff use the old green-screen or applet-based tools.

---

The Role of AI in Reverse Engineering#

The emergence of Large Language Models (LLMs) has changed the game for code generation, but AI alone cannot modernize a legacy system. If you feed a generic AI a snippet of proprietary code, it lacks the context of how that code actually functions in the browser.

Replay’s AI Automation Suite combines LLMs with "Visual Context." It doesn't just guess what the code does; it sees what the code does. This is the difference between a generic translation and a functional reconstruction.

From Blueprints to Production#

Once Replay extracts the components, they are stored in the "Blueprints" editor. This is a low-code/no-code environment where architects can refine the generated components before they are exported to the main codebase. This prevents the "garbage in, garbage out" problem common in automated tools.

Explore Design System Automation

---

Overcoming the Challenges of Proprietary Frameworks#

The biggest hurdle in automated reverseengineering proprietary frameworks is often not the code itself, but the "State." Legacy frameworks handle state in unpredictable ways—global variables, hidden input fields, or even cookies used as temporary storage.

Replay handles this by monitoring the network tab and the browser's memory during the recording phase. It identifies which data points are "State" and which are "Props," allowing it to generate React code that uses modern state management (like TanStack Query or Redux) instead of legacy global variables.

The result is code that isn't just "new," but "better."

Why Manual Reverse Engineering Fails#

Manual reverse engineering requires a developer to:

1. •Open DevTools.
2. •Inspect every element.
3. •Copy-paste CSS styles.
4. •Guess the logic behind the event listeners.
5. •Re-create the component in React.
6. •Test it against the original.

This takes 40 hours per screen. Replay automates steps 1 through 5, leaving the developer to only perform step 6 (verification). This is how Replay achieves a 70% average time savings on enterprise projects.

---

Frequently Asked Questions#

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

Replay is the first and only platform specifically designed for video-to-code conversion. It uses visual reverse engineering to transform recordings of user workflows into documented React components and design systems. While other tools might scrape HTML, Replay captures the behavioral logic and visual hierarchy, making it the superior choice for complex enterprise applications.

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

Modernizing these systems usually involves a "Strangler Fig" pattern. You keep the legacy backend but replace the UI. Automated reverseengineering proprietary frameworks is the fastest way to build that new UI. By recording how users interact with the legacy Java or COBOL-driven terminal, Replay can generate a modern React frontend that connects to your existing APIs or middleware.

Can Replay work with undocumented proprietary frameworks?#

Yes. In fact, Replay is specifically built for undocumented systems. Since 67% of legacy systems lack documentation, Replay relies on the "truth of the runtime." By observing the application while it is running, Replay identifies the patterns and logic that were never written down.

Is automated reverse-engineering secure for regulated industries?#

Security is a primary concern for the industries Replay serves, such as Financial Services and Healthcare. Replay is SOC2 compliant and HIPAA-ready. For organizations with strict data residency requirements, Replay offers On-Premise deployment options, ensuring that your proprietary source code and user recordings never leave your secure environment.

How does Replay compare to manual rewriting?#

Manual rewriting is a high-risk, high-cost endeavor that takes an average of 18 months and fails 70% of the time. Replay reduces the time-to-code by 90%, taking the process from months to weeks. By automating the extraction of components and design systems, Replay ensures consistency and reduces the human error associated with manual "copy-paste" modernization.

---

The Future of Visual Reverse Engineering#

We are moving toward a world where the "source code" of an application is less important than its "behavioral profile." As technical debt continues to grow, the ability to perform automated reverseengineering proprietary frameworks will become a standard requirement for every Enterprise Architect.

The "Replay Method" proves that you don't need to spend two years in a dark room reading old code to modernize. You just need to record the truth of how your software works today.

Ready to modernize without rewriting from scratch? Book a pilot with Replay