MUMPS Code Extraction: Moving Legacy Patient Records to Modern React UI in Healthcare

The $3.6 trillion global technical debt crisis has a silent, green-screened epicenter: the healthcare sector. While modern fintech and e-commerce scale on cloud-native stacks, the backbone of global patient care—including systems like VistA and legacy Epic modules—often runs on MUMPS (Massachusetts General Hospital Utility Multi-Programming System). This 1960s-era language is responsible for millions of patient records, yet it remains a "black box" that costs hospitals millions in maintenance and missed innovation opportunities.

Traditional mumps code extraction is a digital archaeology project that most CIOs can no longer afford. With 70% of legacy rewrites failing or exceeding their timelines, the industry needs a shift from manual code analysis to automated, visual reverse engineering.

TL;DR: Manual MUMPS code extraction is a high-risk, slow-burn failure; Replay uses visual reverse engineering to document and migrate legacy healthcare workflows into modern React components with a 70% reduction in timeline.

Why Manual MUMPS Code Extraction is a Billion-Dollar Mistake#

In my experience as an Enterprise Architect, I’ve seen healthcare organizations attempt to "crack the nut" of MUMPS by hiring expensive consultants to manually read thousands of lines of unstructured code. The results are almost always the same: missed edge cases, broken business logic, and a project that stalls at the 18-month mark.

MUMPS is unique—and uniquely difficult. It combines a programming language with a hierarchical database (Globals) that lacks a rigid schema. When you attempt manual mumps code extraction, you aren't just reading code; you are trying to guess how a non-relational database from 1966 interacts with a modern clinical workflow.

The Documentation Gap#

Statistics show that 67% of legacy systems lack any form of current documentation. In healthcare, this isn't just a technical hurdle; it’s a compliance risk. When the original developers of a MUMPS-based Patient Administration System (PAS) have retired, the "source of truth" resides only in the live environment.

The Cost of Human Error#

A manual rewrite of a single legacy screen typically takes 40 hours of engineering time. This includes discovery, logic mapping, UI design, and testing. For a hospital system with 500+ screens, that is 20,000 man-hours—roughly $3 million in labor alone, excluding the opportunity cost of delayed modernization.

Moving From "Code Archaeology" to Visual Reverse Engineering#

The future of healthcare modernization isn't in reading the code; it’s in understanding the intent. At Replay, we advocate for a "Video as Source of Truth" model. Instead of performing traditional mumps code extraction by parsing cryptic

files, we record the actual clinical workflows as they happen.

How Visual Reverse Engineering Works#

When a nurse enters patient vitals into a legacy terminal, that interaction contains the complete business logic of the system. Replay captures this "Shadow DOM" of the legacy interface, mapping the inputs, outputs, and state transitions.

By observing the system in action, Replay bypasses the need to understand the underlying MUMPS Globals. We extract the behavior and translate it directly into modern React components and API contracts. This reduces the time per screen from 40 hours to just 4 hours.

💡 Pro Tip: Don't start your modernization project by looking at the database schema. Start by recording the top 10 most frequent user workflows. This identifies the "hot paths" that provide the most immediate ROI.

Technical Deep Dive: From MUMPS to React#

The primary challenge in mumps code extraction is the translation of procedural, terminal-based logic into functional, component-based architecture. MUMPS uses global variables (e.g.,

) to store patient data. A modern React UI needs a structured JSON response from a REST or GraphQL API.

Replay’s AI Automation Suite bridges this gap by generating the TypeScript interfaces and React hooks required to interact with these legacy data layers.

Example: Extracted Patient Record Component#

Below is a representation of what Replay generates after observing a user navigate a patient record screen in a MUMPS-based system.

typescript
// Generated by Replay Visual Reverse Engineering
// Source: Legacy VistA Patient Inquiry Screen
import React, { useState, useEffect } from 'react';
import { PatientService } from '@/services/legacy-bridge';
import { Card, Spinner, Alert } from '@/components/ui';

interface PatientData {
  dfn: string;
  name: string;
  dob: string;
  ssn: string; // Masked per HIPAA compliance
  lastAdmission: string;
}

export const PatientModernView: React.FC<{ patientId: string }> = ({ patientId }) => {
  const [data, setData] = useState<PatientData | null>(null);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    // Replay generated the API contract based on observed MUMPS global outputs
    PatientService.getInquiry(patientId)
      .then(res => setData(res))
      .catch(err => console.error("Extraction mapping error", err))
      .finally(() => setLoading(false));
  }, [patientId]);

  if (loading) return <Spinner />;
  if (!data) return <Alert>Patient record not found in legacy global.</Alert>;

  return (
    <Card title="Patient Summary">
      <div className="grid grid-cols-2 gap-4">
        <label>Full Name</label>
        <span>{data.name}</span>
        <label>DOB</label>
        <span>{data.dob}</span>
        {/* Business logic for admission status preserved from legacy flow */}
        <div className="status-indicator">
          Last Admission: {data.lastAdmission}
        </div>
      </div>
    </Card>
  );
};

Preserving Business Logic Without the Headache#

The logic within MUMPS is often deeply nested. For example, a "simple" patient registration might involve 15 different validation checks scattered across multiple routines.

When you use Replay for mumps code extraction, the platform identifies these validation triggers during the recording phase. It creates an E2E test suite that ensures the new React UI behaves exactly like the legacy terminal, catching discrepancies before they reach production.

⚠️ Warning: Never attempt a "lift and shift" of MUMPS logic into JavaScript. The paradigms are too different. Instead, use the extracted behavior to define a clean API contract.

A 3-Step Guide to Modernizing Legacy Patient Records#

For Enterprise Architects in healthcare, the following framework provides a low-risk path to moving away from MUMPS.

Step 1: Visual Assessment & Recording#

Instead of a code audit, conduct a "Workflow Audit." Use Replay to record clinicians performing routine tasks—patient intake, billing, and lab result entry. This creates a "Blueprint" of the system's actual usage, rather than its theoretical design.

Step 2: Extraction and Design System Mapping#

Replay’s AI Suite analyzes the recordings to identify recurring UI patterns. It automatically populates your "Library" (Design System) with React components that mirror the legacy functionality but utilize modern UX principles. This is where the 70% time savings are realized.

Step 3: API Contract Generation & Integration#

Once the UI is extracted, Replay generates the necessary API contracts (OpenAPI/Swagger). These serve as the "bridge" between your new React frontend and the legacy MUMPS backend (often exposed via an integration engine like InterSystems IRIS or a custom RPC broker).

💰 ROI Insight: By reducing the migration timeline from 18 months to 3 months, a mid-sized hospital system can save approximately $1.2 million in developer salaries and consultant fees.

Addressing Regulated Environment Concerns (HIPAA & SOC2)#

In healthcare, data residency and security are non-negotiable. Traditional SaaS tools that require uploading sensitive patient data to the cloud are often rejected by compliance teams.

Replay is built for these environments. It offers an On-Premise deployment model, ensuring that during the mumps code extraction process, Protected Health Information (PHI) never leaves your secure network. The platform is HIPAA-ready and SOC2 compliant, providing the technical debt audit trails required for regulatory oversight.

Technical Debt Audit#

One of the most overlooked features of Replay is the Technical Debt Audit. As it extracts the legacy workflows, it identifies redundant routines and dead code paths in the MUMPS environment. This allows your team to decommission parts of the legacy system safely, reducing the overall footprint of the "black box."

The Future of Legacy Modernization#

The era of the "Big Bang" rewrite is over. The $3.6 trillion technical debt problem won't be solved by throwing more developers at 50-year-old codebases. It will be solved by understanding what we already have.

By utilizing Replay for mumps code extraction, healthcare organizations can finally unlock their patient data. You move from a state of "maintenance mode" to "innovation mode" in weeks, not years. You stop being a digital archaeologist and start being a digital architect.

📝 Note: Successful modernization requires a culture shift. Transitioning from MUMPS to React isn't just a change in syntax; it's a change in how the organization views data accessibility and user experience.

Frequently Asked Questions#

How long does mumps code extraction take with Replay?#

While a manual extraction and rewrite of a complex clinical screen can take 40-60 hours, Replay reduces this to approximately 4 hours. Most enterprise pilots see a fully functional, documented React prototype of their core workflows within 2 to 4 weeks.

Does Replay require access to the MUMPS source code?#

No. Replay uses visual reverse engineering. By recording the user workflows in the legacy terminal or web-wrapper, Replay understands the inputs, outputs, and logic transitions. This makes it ideal for systems where the source code is poorly documented or the original developers are unavailable.

How does Replay handle complex healthcare business logic?#

Replay captures the "state changes" in the application. If a specific input in the legacy system triggers a specific output or validation error, Replay documents that logic. It then generates E2E tests and API contracts that ensure the new React system replicates that behavior perfectly.

Is Replay HIPAA compliant?#

Yes. Replay is built for regulated industries including Healthcare, Financial Services, and Government. We offer On-Premise installations so that PHI and sensitive business logic never leave your infrastructure. We are also SOC2 Type II compliant.

Can Replay generate E2E tests for my legacy system?#

Yes. One of the primary outputs of the Replay extraction process is a comprehensive suite of Playwright or Cypress tests. These tests ensure that your modernized React UI remains functionally equivalent to the legacy MUMPS system during the entire migration lifecycle.

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Ready to modernize without rewriting? Book a pilot with Replay - see your legacy screen extracted live during the call.