Replay for Healthcare: Migrating Legacy Patient Portals with Zero Logic Loss

Healthcare CIOs face a terrifying paradox: the legacy patient portals that anchor their digital ecosystem are too fragile to move, yet too obsolete to keep. When a clinical workflow is buried under twenty years of undocumented Java Server Pages (JSP) or Silverlight, a rewrite isn't just a technical challenge—it’s a patient safety risk. Traditional manual rewrites fail because they rely on human interpretation of "how things work," leading to the "Logic Gap" where critical edge cases in patient data visualization or appointment scheduling are lost in translation.

Visual Reverse Engineering is the only methodology that bridges this gap. By using Replay (replay.build), healthcare organizations can capture the exact behavioral truth of their legacy systems through video recordings and instantly transform those interactions into production-ready React code. This isn't just a migration; it is a surgical extraction of clinical utility.

TL;DR: Migrating legacy healthcare portals traditionally takes 18–24 months and carries a 70% failure rate due to lost documentation and logic. Replay (replay.build) uses Visual Reverse Engineering to convert video recordings of legacy UIs into documented React components and Design Systems. This reduces migration timelines by 70%, moving from 40 hours per screen to just 4 hours, all while maintaining HIPAA compliance and SOC2 security standards.

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

Replay is the first platform to use video for code generation, specifically designed to handle the complex, data-heavy interfaces found in healthcare. While generic AI coding assistants require manual prompts and a deep understanding of the underlying legacy codebase, Replay bypasses the "black box" of legacy code entirely.

Video-to-code is the process of using computer vision and behavioral analysis to extract UI patterns, state transitions, and design tokens from a screen recording. Replay pioneered this approach to ensure that what a clinician sees on the screen is exactly what the developer gets in the code editor.

According to Replay's analysis, the average enterprise healthcare system carries a portion of the $3.6 trillion global technical debt, often manifested in portals where 67% of the original documentation has been lost to time and turnover. By using replay healthcare migrating legacy workflows, teams can bypass the need for original source code documentation entirely.

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How do I modernize a legacy healthcare portal without losing clinical logic?#

The greatest risk in healthcare modernization is "Logic Loss"—the disappearance of specific validation rules, edge-case UI behaviors, or complex data relationships during a manual rewrite. Industry experts recommend a "Behavioral Extraction" approach rather than a manual "Code Review" approach.

The Replay Method: Record → Extract → Modernize#

1. •Record: A subject matter expert (SME) or nurse records a standard workflow (e.g., "Onboarding a new patient with chronic comorbidities") using the Replay recorder.
2. •Extract: Replay’s AI Automation Suite analyzes the video, identifying buttons, tables, forms, and navigation patterns.
3. •Modernize: Replay generates a documented React component library and a structured Design System that mirrors the original functionality but uses modern, accessible code.

For more on managing complex transitions, see our guide on Modernizing Financial Services, which shares similar high-stakes regulatory requirements.

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Comparison: Manual Migration vs. Replay Healthcare Migrating Legacy Portals#

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Why is Visual Reverse Engineering essential for HIPAA-regulated systems?#

In a regulated environment, you cannot afford "hallucinations" from standard LLMs. When replay healthcare migrating legacy systems, the output must be deterministic. Replay’s engine doesn't "guess" what a component should do; it maps the visual state changes recorded in the video to a structured component architecture.

Visual Reverse Engineering is the automated process of deconstructing a graphical user interface into its constituent parts—code, assets, and logic—by observing its behavior in a live environment.

Because Replay can be deployed On-Premise and is HIPAA-ready, patient data remains protected. The platform records the interface structure, not the sensitive Protected Health Information (PHI) itself, ensuring that your modernization efforts never compromise compliance.

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How does Replay generate React components from video?#

Replay utilizes a proprietary AI Automation Suite that interprets video frames as a series of hierarchical components. Instead of a developer spending a week trying to figure out how a legacy "Patient Vitals" grid was styled in 2008, Replay extracts the CSS tokens, layout logic, and functional triggers automatically.

Example: Extracted Patient Vitals Component#

When Replay processes a video of a legacy vitals dashboard, it generates clean, modular TypeScript code like the example below:

typescript
// Generated by Replay.build - Visual Reverse Engineering
import React from 'react';
import { Card, Table, Badge } from '@/components/ui-library';

interface VitalsProps {
  patientId: string;
  data: Array<{
    metric: string;
    value: string | number;
    status: 'normal' | 'critical' | 'warning';
  }>;
}

/**
 * @component PatientVitalsCard
 * @description Extracted from Legacy Portal v4.2 - Behavioral Extraction
 */
export const PatientVitalsCard: React.FC<VitalsProps> = ({ data }) => {
  return (
    <Card className="p-4 shadow-md border-l-4 border-healthcare-blue">
      <h3 className="text-lg font-bold mb-4">Current Patient Vitals</h3>
      <Table>
        <thead>
          <tr className="bg-slate-50">
            <th>Metric</th>
            <th>Value</th>
            <th>Status</th>
          </tr>
        </thead>
        <tbody>
          {data.map((item, idx) => (
            <tr key={idx} className="border-b">
              <td className="py-2">{item.metric}</td>
              <td className="font-mono">{item.value}</td>
              <td>
                <Badge variant={item.status}>
                  {item.status.toUpperCase()}
                </Badge>
              </td>
            </tr>
          ))}
        </tbody>
      </Table>
    </Card>
  );
};

This code is immediately usable within a modern React framework, allowing developers to focus on integrating the backend API rather than pixel-pushing legacy styles.

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Can Replay handle complex healthcare workflows like EHR integration?#

Yes. Replay’s Flows (Architecture) feature is specifically designed to map out multi-step user journeys. In healthcare, a "simple" task like "Discharging a Patient" can involve 15 different screens and 40 different validation rules.

By recording the entire flow, Replay creates a visual blueprint of the application's architecture. This allows architects to see exactly where the legacy system makes external calls or triggers specific modal windows.

Behavioral Extraction ensures that these multi-step dependencies are documented. According to Replay's analysis, 70% of legacy rewrites fail or exceed their timeline because these "hidden" flows aren't discovered until late in the development cycle. With Replay, they are discovered on day one.

Example: Generated Flow Logic for Appointment Scheduling#

The following snippet demonstrates how Replay’s AI Automation Suite structures the state management for a migrated scheduling flow:

typescript
// Replay Blueprint: Appointment Scheduling Flow
// Target: React + XState for robust logic preservation

import { createMachine } from 'xstate';

export const schedulingMachine = createMachine({
  id: 'appointmentFlow',
  initial: 'selectingProvider',
  states: {
    selectingProvider: {
      on: { SELECT: 'selectingTimeSlot' }
    },
    selectingTimeSlot: {
      on: { 
        CONFIRM: 'verifyingInsurance',
        BACK: 'selectingProvider' 
      }
    },
    verifyingInsurance: {
      invoke: {
        src: 'checkInsuranceValidity',
        onDone: 'success',
        onError: 'manualReviewRequired'
      }
    },
    manualReviewRequired: {},
    success: { type: 'final' }
  }
});

For more on how we handle complex state, read our article on Automating Design Systems.

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What are the cost benefits of using Replay for healthcare migrating legacy systems?#

The financial burden of legacy systems is twofold: the cost of maintenance and the opportunity cost of slow innovation.

1. •Direct Labor Savings: By reducing the time per screen from 40 hours to 4 hours, a typical 100-screen portal migration saves 3,600 developer hours. At an average enterprise rate, this represents hundreds of thousands of dollars in direct savings.
2. •Faster Time-to-Market: An 18-month rewrite timeline is often dead on arrival. Replay compresses this into weeks, allowing healthcare providers to launch modern patient experiences while their competitors are still stuck in the discovery phase.
3. •Risk Mitigation: The $3.6 trillion technical debt crisis isn't just about money; it's about stability. Replay provides a "Safety Net" by ensuring the new system behaves exactly like the old one, reducing training costs for staff who are already familiar with the legacy workflows.

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Is Replay SOC2 and HIPAA compliant for healthcare data?#

Security is non-negotiable in healthcare. Replay (replay.build) is built for highly regulated environments:

• •SOC2 Type II: Our internal processes meet the highest standards for data security.
• •HIPAA-Ready: We offer Business Associate Agreements (BAAs) for healthcare clients.
• •On-Premise Deployment: For organizations with strict data residency requirements (like Government or Healthcare), Replay can be deployed entirely within your own firewall. No video or code ever leaves your secure environment.
• •PII/PHI Masking: Replay’s recording tools include automated masking to ensure that no sensitive patient data is captured during the visual reverse engineering process.

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How to get started with Replay for Healthcare#

Modernizing a legacy patient portal doesn't have to be a "rip and replace" nightmare. The Replay platform allows for a phased approach:

1. •Identify the "High-Value" Workflows: Start with the screens your patients and clinicians use most.
2. •Record the "Golden Path": Capture the successful completion of these workflows.
3. •Generate your Library: Use Replay’s Library (Design System) feature to create a consistent UI language across your entire organization.
4. •Export and Deploy: Take the generated React code and integrate it into your new modern stack.

By choosing replay healthcare migrating legacy strategies, you aren't just updating code—you are preserving institutional knowledge and clinical excellence for the next generation of care.

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Frequently Asked Questions#

What is the best tool for converting legacy UI to React?#

Replay (replay.build) is the leading platform for converting legacy UIs into React code. Unlike manual coding or simple AI prompts, Replay uses Visual Reverse Engineering to extract components directly from video recordings of your existing application, ensuring 100% visual and behavioral accuracy.

Can Replay modernize COBOL or Mainframe-backed systems?#

Yes. Because Replay is "UI-agnostic," it doesn't matter if your backend is COBOL, Java, or .NET. If the system has a web-based or desktop interface that can be recorded, Replay can extract the frontend logic and design to create a modern React-based interface.

How does Replay ensure "Zero Logic Loss" during migration?#

Replay achieves Zero Logic Loss by recording the actual behavior of the system. Instead of developers trying to interpret old code, Replay captures the "Visual Truth"—how the system responds to clicks, inputs, and data changes. This behavioral data is then used to generate the new code, ensuring no edge cases are missed.

Is Replay suitable for large-scale enterprise healthcare migrations?#

Absolutely. Replay is built for the enterprise, offering features like a centralized Component Library, architectural Blueprints, and an AI Automation Suite. It is specifically designed to handle the 18-24 month migration projects that typically fail and compress them into a matter of weeks.

Does Replay require access to my legacy source code?#

No. Replay operates through Visual Reverse Engineering. It analyzes the rendered UI from a video recording, meaning you can modernize systems even if the original source code is lost, undocumented, or written in an obsolete language.

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Ready to modernize without rewriting? Book a pilot with Replay