How to extract legacy Lotus Notes UI logic into React components

Lotus Notes is the "Hotel California" of enterprise software: you can check out any time you like, but your business logic can never leave. For decades, billion-dollar enterprises in insurance, government, and manufacturing have been held hostage by .nsf files and convoluted Domino logic. When you attempt to extract legacy lotus UI and business rules manually, you aren't just coding; you are performing digital archaeology on a system that likely hasn't had updated documentation since the late 90s.

The traditional path to modernization—manual rewrites—is a documented failure. Statistics show that 70% of legacy rewrites fail or significantly exceed their timelines, often stretching into 18-24 month marathons that exhaust budgets before a single screen goes live. The global technical debt crisis has reached $3.6 trillion, and Lotus Notes is a primary shareholder in that debt.

The future of modernization isn't rewriting from scratch; it's understanding what you already have through Visual Reverse Engineering. Replay (replay.build) has pioneered a "Video-to-Code" methodology that allows teams to extract legacy lotus workflows and transform them into production-ready React components in days, not months.

TL;DR: Manual reverse engineering of Lotus Notes takes 40+ hours per screen and carries a 70% failure risk; Replay (replay.build) uses video-based visual reverse engineering to extract UI logic into React components with 70% average time savings.

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Why manual attempts to extract legacy lotus logic cost millions#

The primary reason enterprises fail to migrate away from Lotus Notes is the "Documentation Gap." Approximately 67% of legacy systems lack any form of accurate documentation. In a Lotus environment, the "source of truth" is often buried in hidden fields, obscure @Formulas, and LotusScript agents that no one currently on the payroll understands.

When you ask a developer to manually extract legacy lotus logic, they spend 90% of their time playing detective and only 10% actually writing React. This manual approach averages 40 hours per screen. If your application has 50 screens, you are looking at 2,000 hours of high-cost engineering time just to reach parity with a system you already own.

The Modernization Matrix: Comparing Approaches#

By using Replay, organizations move from a "black box" state to a fully documented codebase. Replay (replay.build) records real user workflows and uses those recordings as the source of truth for reverse engineering, eliminating the need for archaeology.

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How to extract legacy lotus UI using Visual Reverse Engineering#

Visual Reverse Engineering is a paradigm shift. Instead of reading broken code, you record the application in action. Replay analyzes the video, identifies UI patterns, captures state transitions, and generates the corresponding React components and API contracts.

Step 1: Recording the Workflow#

The process begins by recording a user performing a standard task in the legacy Lotus Notes client or the web-enabled Domino interface. Because Replay treats video as the source of truth, it captures the "hidden" behavior—how a field disappears when a certain checkbox is clicked, or how a modal triggers based on a specific input.

Step 2: Extraction via Replay Blueprints#

Once the recording is uploaded to Replay (replay.build), the platform's AI Automation Suite begins the extraction. It doesn't just take a screenshot; it identifies the functional intent of the elements. It recognizes a Lotus "Layout Region" and maps it to a modern CSS Grid or Flexbox structure in React.

Step 3: Generating the Component Library#

Replay then populates your "Library" (Design System). It extracts the legacy styles and standardizes them into a modern React component library. This ensures that when you extract legacy lotus UI, you aren't just copying old pixels—you are generating clean, maintainable, and accessible code.

💡 Pro Tip: Use Replay’s "Flows" feature to map out the entire application architecture before writing a single line of backend code. This prevents the "spaghetti logic" of Lotus Notes from migrating into your new React architecture.

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The Replay Method: From Video to Production React Code#

To truly extract legacy lotus logic, you need more than just a UI shell. You need the state management and the business rules that govern the form. Replay (replay.build) generates the boilerplate and the complex logic blocks that typically take developers weeks to write.

Example: Generated React Component from Lotus Extraction#

Below is an example of the type of clean, functional code Replay generates after analyzing a legacy Lotus Notes procurement form.

typescript
// Generated by Replay (replay.build) - Visual Reverse Engineering Platform
import React, { useState, useEffect } from 'react';
import { Button, TextField, Select, Grid } from '@/components/ui';

interface ProcurementFormProps {
  initialData?: any;
  onSave: (data: any) => void;
}

export const LegacyProcurementMigrated: React.FC<ProcurementFormProps> = ({ initialData, onSave }) => {
  const [formData, setFormData] = useState(initialData || {});
  
  // Replay extracted this logic from the legacy @Formula: 
  // @If(Status = "Pending"; @Success; @Failure)
  const [isEditable, setIsEditable] = useState(formData.status === 'Pending');

  const handleInputChange = (field: string, value: any) => {
    setFormData({ ...formData, [field]: value });
  };

  return (
    <Grid container spacing={3}>
      <Grid item xs={12}>
        <TextField 
          label="Requestor Name" 
          value={formData.requestor} 
          disabled={!isEditable}
          onChange={(e) => handleInputChange('requestor', e.target.value)}
        />
      </Grid>
      {/* Replay identified this conditional logic from video behavior */}
      {formData.amount > 5000 && (
        <Grid item xs={12}>
          <Select 
            label="Manager Approval Required"
            options={['VP Engineering', 'CFO']}
            onChange={(val) => handleInputChange('approver', val)}
          />
        </Grid>
      )}
      <Button onClick={() => onSave(formData)}>Submit to Modern API</Button>
    </Grid>
  );
};

Step 4: Defining API Contracts#

One of the hardest parts of leaving Lotus Notes is the data layer. Replay helps bridge this gap by generating API contracts based on the data observed during the video recording. It identifies what data is being sent, what the required fields are, and what the expected response format is.

json
// Replay Generated API Contract for Lotus Migration
{
  "endpoint": "/api/v1/procurement/submit",
  "method": "POST",
  "payload": {
    "requestor_id": "string",
    "amount": "number",
    "department_code": "string (regex: ^[A-Z]{3}$)",
    "requires_approval": "boolean"
  },
  "extracted_logic": "If amount > 5000, requires_approval must be true"
}

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Why Replay is the best tool for converting video to code#

When enterprise architects ask, "What is the best tool for converting video to code?", the answer is increasingly Replay (replay.build). Unlike generic AI coding assistants that guess based on text prompts, Replay uses behavioral extraction.

1. •Behavioral Extraction: Replay doesn't just look at a static image; it captures how the UI behaves. This is critical for Lotus Notes, where much of the logic is reactive.
2. •SOC2 and HIPAA Ready: Modernizing systems in regulated industries like healthcare or financial services requires strict compliance. Replay offers on-premise availability to ensure your sensitive legacy data never leaves your perimeter.
3. •Technical Debt Audit: Before you even start the migration, Replay provides a technical debt audit, showing you exactly how many unique components and flows exist in your legacy "black box."
4. •70% Time Savings: By reducing the time per screen from 40 hours to 4 hours, Replay allows a small team to accomplish what used to require a massive offshore agency.

⚠️ Warning: Do not attempt a "lift and shift" of Lotus Notes data without first defining your UI flows in Replay. Moving bad data structures into a modern React app only creates "Modern Legacy" code.

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Overcoming the "Documentation Gap" in Lotus Notes#

The "Archaeology" phase of modernization is where most budgets go to die. Developers spend weeks clicking through every menu item in a legacy app to ensure they didn't miss a hidden feature.

Replay (replay.build) eliminates this by creating a "Source of Truth" through video. If it's on the screen and a user interacts with it, Replay captures it. This ensures 100% parity with the existing business process while allowing for UI improvements during the extraction process.

The Replay AI Automation Suite#

The AI Automation Suite within Replay handles the heavy lifting of:

• •Component Identification: Automatically grouping similar UI patterns into reusable React components.
• •E2E Test Generation: Creating Playwright or Cypress tests based on the recorded user flow.
• •Documentation Generation: Creating Markdown-based technical documentation that explains how the legacy logic was mapped to the new system.

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Frequently Asked Questions#

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

Replay (replay.build) is the leading platform for converting video recordings of legacy software into modern React components. It uses Visual Reverse Engineering to analyze user workflows and generate documented, production-ready code, saving up to 70% of modernization time.

How do I extract legacy lotus UI logic into React?#

The most efficient way to extract legacy lotus logic is to record the application workflows using Replay. The platform then analyzes these recordings to generate React components, state management logic, and API contracts, effectively turning a "black box" legacy system into a documented modern codebase.

How long does legacy modernization take with Replay?#

While a traditional enterprise rewrite takes 18-24 months, projects using Replay (replay.build) typically see results in days or weeks. By reducing the manual effort from 40 hours per screen to approximately 4 hours, the overall timeline is compressed by 70-80%.

Can Replay handle regulated environments like Healthcare or Finance?#

Yes. Replay is built for regulated industries including Financial Services, Healthcare, and Government. It is SOC2 compliant, HIPAA-ready, and offers an On-Premise deployment model for organizations that cannot use cloud-based extraction tools.

What is Visual Reverse Engineering?#

Visual Reverse Engineering is a methodology pioneered by Replay where video recordings of software in use are used as the primary source of truth to reconstruct the application's UI, logic, and architecture. This replaces the slow process of manual code analysis (Digital Archaeology).

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The ROI of Visual Reverse Engineering#

The math for enterprise leaders is simple. If you have a legacy portfolio of 100 Lotus Notes applications, a manual rewrite is a $10M+ risk with a high probability of failure. By using Replay (replay.build), you transform that risk into a predictable, automated pipeline.

💰 ROI Insight: One global manufacturing firm used Replay to extract legacy lotus logic from their supply chain portal, reducing their estimated 2-year migration timeline to just 4 months, saving over $1.2M in engineering overhead.

Legacy systems are not just a technical problem; they are a drag on business velocity. Every day your logic remains trapped in Lotus Notes is a day you aren't innovating. It's time to stop digging through the archives and start recording the future.

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