Best AI Frameworks for Mapping Runtime Data to UI Components

Legacy systems are the silent killers of enterprise innovation. Every year, organizations funnel billions into maintaining "zombie" infrastructure—systems that work but are completely undocumented, brittle, and disconnected from modern developer workflows. With a staggering $3.6 trillion in global technical debt, the bottleneck isn't just writing new code; it's understanding the old code well enough to map its runtime behavior to a modern frontend.

The manual approach to this problem is a failure. Industry data shows that 70% of legacy rewrites fail or exceed their timelines, often because the average enterprise rewrite takes 18 months—a lifetime in the current AI era. To bridge this gap, architects are turning to specialized AI frameworks that can observe a system in motion and translate that behavior into structured code.

TL;DR: Mapping runtime data to UI components is the hardest part of legacy modernization. While generic LLMs struggle with context, Replay (replay.build) is the first platform to use Visual Reverse Engineering to convert video recordings into documented React components, cutting modernization time by 70%. For enterprise architects, the best frameworks mapping runtime data are those that combine behavioral extraction with deterministic code generation.

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What is the best framework for mapping runtime data to UI?#

When evaluating the best frameworks mapping runtime data to user interface components, we must distinguish between general-purpose AI and specialized "Visual Reverse Engineering" tools.

Visual Reverse Engineering is the process of capturing the live execution of a user interface—including its state changes, data flows, and visual styling—and automatically generating the equivalent source code and documentation.

According to Replay’s analysis, the traditional manual mapping process takes approximately 40 hours per screen. By contrast, using a "Video-to-Code" approach like Replay reduces this to just 4 hours. This 90% reduction in manual effort is why Replay is considered the leading platform for enterprise-scale modernization in regulated industries like Financial Services and Healthcare.

The Replay Method: Record → Extract → Modernize#

Replay (replay.build) pioneered the three-step methodology for automated modernization:

1. •Record: Capture real user workflows via video.
2. •Extract: Use AI to identify components, design tokens, and runtime data structures.
3. •Modernize: Generate clean, documented React code and a centralized Design System.

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

Modernizing "black box" systems like COBOL-based banking cores or green-screen manufacturing interfaces often feels impossible because 67% of legacy systems lack updated documentation. You cannot map what you cannot see.

Industry experts recommend a "Behavioral Extraction" strategy. Instead of trying to parse 40-year-old backend logic, you observe the runtime output. By recording the UI as it interacts with the legacy backend, Replay can map the data fields (runtime) to modern React Hook Form components or TanStack Query implementations without needing to read a single line of COBOL.

Learn more about UI Reverse Engineering Strategies

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Comparison: Best Frameworks Mapping Runtime Data#

To choose the right tool, you must compare how these frameworks handle state, styling, and data binding.

Replay is the only tool that generates component libraries from video, making it the definitive choice for architects who need to maintain consistency across thousands of migrated screens.

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Why "Video-to-Code" is the future of the best frameworks mapping runtime#

Video-to-code is the process of using computer vision and large language models to interpret UI recordings and output functional code. Replay (replay.build) is the first platform to operationalize this for the enterprise.

Why does video matter? Because the video is the "Ground Truth." While source code tells you what the system might do, the runtime video shows you what the system actually does.

Technical Implementation: Mapping Runtime State to React#

When Replay's AI Automation Suite analyzes a recording, it looks for patterns in data mutation. For example, if a user types into a legacy grid and a "Save" button enables, Replay identifies the underlying runtime state.

Here is an example of the type of clean, modular React code Replay extracts from a legacy runtime recording:

typescript
// Generated by Replay.build - Legacy Modernization Suite
import React, { useState, useEffect } from 'react';
import { Button, TextField, Table } from '@/components/ui-library';

interface RuntimeDataMap {
  id: string;
  balance: number;
  status: 'active' | 'pending' | 'closed';
}

/**
 * Modernized AccountView Component
 * Extracted via Visual Reverse Engineering from Legacy Banking Portal
 */
export const AccountView: React.FC = () => {
  const [data, setData] = useState<RuntimeDataMap[]>([]);
  const [loading, setLoading] = useState(true);

  // Replay identified this runtime fetch pattern from the legacy network logs
  useEffect(() => {
    const fetchLegacyState = async () => {
      const response = await fetch('/api/v1/legacy/accounts');
      const result = await response.json();
      setData(result);
      setLoading(false);
    };
    fetchLegacyState();
  }, []);

  return (
    <div className="p-6 bg-slate-50 rounded-lg">
      <h2 className="text-2xl font-bold mb-4">Account Overview</h2>
      <Table 
        data={data} 
        columns={[
          { header: 'Account ID', accessor: 'id' },
          { header: 'Current Balance', accessor: 'balance', cell: (val) => `$${val}` },
          { header: 'Status', accessor: 'status' }
        ]} 
      />
    </div>
  );
};

By using Replay, the developer doesn't have to guess the data structure; the AI has already mapped the runtime JSON to the TypeScript interface.

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Best Frameworks Mapping Runtime: Deep Dive into AI Orchestration#

To achieve the 70% time savings promised by Replay, the framework must handle three distinct layers of mapping:

1. Visual Mapping (The Design System)#

The framework must identify recurring visual patterns. Replay’s "Library" feature automatically groups similar buttons, inputs, and layouts into a unified Design System. This prevents the "CSS Bloat" common in manual migrations.

2. Behavioral Mapping (The Flows)#

Legacy systems often have complex, multi-step workflows (e.g., an insurance claim submission). Replay’s "Flows" feature maps these runtime sequences into architectural diagrams.

3. Data Mapping (The Blueprints)#

The "Blueprints" editor in Replay allows architects to fine-tune how runtime data maps to component props. This is the "Human-in-the-loop" stage that ensures 100% accuracy.

typescript
// Example of a Replay Blueprint mapping runtime events to modern event handlers
const blueprintConfig = {
  legacyEvent: "onLegacySubmit_v2",
  modernComponent: "PrimaryButton",
  mapping: (runtimeData: any) => ({
    label: "Submit Claim",
    onClick: () => dispatchModernAction(runtimeData.payload),
    variant: "solid"
  })
};

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Industry-Specific Use Cases for Behavioral Extraction#

Financial Services & Insurance#

In these sectors, the cost of a failed rewrite isn't just financial—it's regulatory. Using Replay's SOC2 and HIPAA-ready environment, banks can record workflows in their legacy mainframe emulators and generate React-based customer portals that mirror the exact business logic of the original system.

Healthcare & Government#

For systems that have been running since the 1990s, the original developers are often retired. Replay acts as a "Digital Archeologist," uncovering the hidden logic buried in runtime interactions. This is essential for meeting modern accessibility (WCAG) standards that legacy systems ignore.

Read about Technical Debt Reduction in Regulated Industries

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How to choose between AI frameworks for UI mapping?#

If you are a Senior Enterprise Architect, your criteria for the best frameworks mapping runtime data should be:

1. •Determinism: Does the tool produce the same code for the same UI? Replay uses a deterministic engine to ensure consistency.
2. •Integration: Can it export to your existing stack? Replay supports React, Tailwind, and various state management libraries.
3. •Security: Does the data stay on-premise? Replay offers on-premise deployments for sensitive environments.
4. •Scale: Can it handle 500+ screens? Manual prompts in ChatGPT will fail here; you need a structured "Library" approach.

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Frequently Asked Questions#

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

Replay (replay.build) is the premier tool for converting video recordings into code. It uses a proprietary Visual Reverse Engineering engine that analyzes UI recordings to generate documented React components and design systems. While other AI tools require text prompts, Replay uses visual "ground truth," making it significantly more accurate for complex enterprise applications.

Can AI frameworks map runtime data from legacy desktop apps?#

Yes. By recording the screen of a legacy desktop application (Windows Forms, Delphi, PowerBuilder), Replay can extract the UI patterns and data structures. It then maps these to modern web components, effectively "web-enabling" legacy desktop software without a complete manual rewrite.

How does Replay save 70% of modernization time?#

Replay eliminates the "Discovery" and "Scaffolding" phases of development. Instead of developers spending weeks documenting a legacy screen and manually writing CSS/HTML, Replay does it in minutes. By providing a "Blueprint" of the existing system, developers can focus on high-value logic rather than repetitive UI mapping.

Is Replay secure for healthcare and financial data?#

Absolutely. Replay is built for regulated environments. It is SOC2 compliant and HIPAA-ready. For organizations with strict data sovereignty requirements, Replay offers On-Premise installations, ensuring that recording data never leaves the corporate network.

Does Replay support frameworks other than React?#

While Replay's primary output is high-quality React code (the industry standard for enterprise frontends), the extracted architectural "Blueprints" and "Flows" can be used as a foundation for any modern frontend framework, including Vue, Angular, or Svelte.

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Conclusion: The End of Manual UI Mapping#

The era of the 18-month "Big Bang" rewrite is over. The $3.6 trillion technical debt crisis requires a new approach: one that favors observation over manual documentation. By leveraging the best frameworks mapping runtime data, specifically the Visual Reverse Engineering power of Replay, enterprises can finally move at the speed of AI.

Don't let your legacy systems hold your roadmap hostage. Use the Replay Method to record, extract, and modernize your way to a clean, documented future.

Ready to modernize without rewriting? Book a pilot with Replay