Modernizing Legacy Semiconductor Design Software for Modern Nodes

The $3.6 trillion global technical debt isn't just a line item on a balance sheet; in the semiconductor industry, it’s a physical barrier to Moore’s Law. As we push toward 2nm nodes and beyond, the software governing EDA (Electronic Design Automation), wafer fabrication management, and supply chain logistics is often stuck in a 1990s time capsule. We are attempting to design the future of silicon using "black box" legacy systems that no one living truly understands.

The traditional approach—the "Big Bang" rewrite—is a suicide mission. Statistics show that 70% of legacy rewrites fail or significantly exceed their timelines. For a semiconductor firm, an 18-24 month delay in modernizing a critical design tool isn't just an IT failure; it’s a catastrophic loss of market share.

TL;DR: Modernizing legacy semiconductor software requires moving away from "technical archaeology" toward Visual Reverse Engineering, reducing modernization timelines from years to weeks by using video as the source of truth.

The High Cost of Technical Archaeology#

Most enterprise architects approach modernizing legacy semiconductor systems like an archaeological dig. They assign senior engineers to spend months "spelunking" through undocumented C++, Java Swing, or even Fortran codebases.

The data is grim: 67% of legacy systems lack any meaningful documentation. When you consider that manual documentation and screen recreation take an average of 40 hours per screen, a complex EDA tool with 200+ screens represents 8,000 man-hours of pure overhead before a single line of modern code is even written.

The Modernization Matrix: Risk vs. Reward#

⚠️ Warning: Attempting a "Big Bang" rewrite of a core semiconductor MES (Manufacturing Execution System) without automated logic extraction is the leading cause of multi-million dollar budget overruns in industrial tech.

Why Semiconductor Software is Different#

Modernizing legacy semiconductor tools presents unique challenges that standard enterprise software doesn't face:

1. •Extreme Precision: Business logic isn't just about "if-then" statements; it involves complex mathematical models for thermal throttling, signal integrity, and lithography simulation.
2. •IP Sensitivity: These systems contain the crown jewels of the company. You cannot simply outsource the rewrite to a third party without massive security risks.
3. •Regulated Environments: Compliance with ISO standards and export controls means every change must be audited.

This is where Replay changes the equation. Instead of reading code to understand the system, Replay records real user workflows. By capturing the interaction between the user and the legacy interface, Replay’s AI Automation Suite performs "Visual Reverse Engineering." It understands what the system does by watching what it produces.

💰 ROI Insight: By switching from manual screen recreation to Replay, firms reduce the time per screen from 40 hours to just 4 hours—a 90% reduction in front-end engineering costs.

From Black Box to Documented React Components#

The future of modernizing legacy semiconductor software isn't rewriting from scratch—it's understanding what you already have and extracting it into a modern stack. Replay allows architects to record a workflow in a legacy tool and instantly generate documented React components, API contracts, and E2E tests.

Example: Extracted Logic from Legacy EDA Tool#

When Replay captures a workflow, it doesn't just copy the UI; it maps the underlying data structures. Below is an example of a modernized React component generated by Replay after observing a legacy wafer-mapping tool.

typescript
// Generated by Replay Visual Reverse Engineering
// Source: Legacy FabView v4.2 (Java Swing)
// Workflow: Wafer Defect Mapping & Categorization

import React, { useState, useEffect } from 'react';
import { WaferMap, DefectTable, ExportButton } from '@semicon-ds/core';

interface DefectData {
  id: string;
  coordinateX: number;
  coordinateY: number;
  severity: 'low' | 'medium' | 'high';
  classification: string;
}

export const ModernizedWaferAnalyzer: React.FC<{ lotId: string }> = ({ lotId }) => {
  const [defects, setDefects] = useState<DefectData[]>([]);
  const [loading, setLoading] = useState(true);

  // Business logic preserved: Replay identified the specific 
  // API endpoint and payload structure from the legacy network trace.
  useEffect(() => {
    async function fetchWaferData() {
      const response = await fetch(`/api/v1/fab/wafer-map/${lotId}`);
      const data = await response.json();
      setDefects(data.points);
      setLoading(false);
    }
    fetchWaferData();
  }, [lotId]);

  return (
    <div className="p-6 bg-slate-900 text-white">
      <header className="flex justify-between mb-4">
        <h2 className="text-xl font-bold">Wafer Analysis: {lotId}</h2>
        <ExportButton data={defects} format="CSV" />
      </header>
      
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-8">
        <WaferMap points={defects} onPointSelect={(p) => console.log(p)} />
        <DefectTable data={defects} />
      </div>
    </div>
  );
};

This isn't just a "reskin." Replay generates the API Contracts and E2E Tests required to ensure the new system behaves exactly like the old one, but with the scalability of a modern web architecture.

The Replay Modernization Framework#

To successfully modernize a legacy semiconductor system, we follow a three-step protocol that prioritizes speed and accuracy over manual labor.

Step 1: Visual Assessment & Recording#

Instead of a 3-month discovery phase, we record the "Golden Workflows." A senior engineer or a power user performs the critical tasks in the legacy system—designing a circuit path, running a simulation, or generating a yield report. Replay records these sessions as the "Source of Truth."

Step 2: Automated Extraction#

Replay’s AI analyzes the recording. It identifies:

• •UI Patterns: Buttons, tables, graphs, and input fields.
• •State Changes: How the data changes as the user interacts.
• •Network Traffic: The underlying API calls (or database queries) that the legacy system makes.

Step 3: Blueprint Generation#

The system generates a Blueprint—a technical audit of the technical debt. From here, you can export:

• •React Components: Clean, modular code for your new UI.
• •Design System: A centralized library of your extracted components.
• •Documentation: Automatically generated technical specs for the new developers.

💡 Pro Tip: Use Replay’s "Library" feature to build a unified Design System across multiple legacy tools. This ensures that your MES, ERP, and EDA tools all share the same look and feel, even if they are modernized at different times.

Preserving Business Logic Without the Archaeology#

The biggest fear in modernizing legacy semiconductor systems is losing the "hidden" business logic—those thousands of edge cases handled by code written 20 years ago.

Replay handles this by generating E2E (End-to-End) Tests based on the recorded video. If the legacy system produced a specific output for a specific input in the video, the new system must do the same. This "Visual Testing" ensures parity without needing to understand every line of the legacy C++ or Java code.

typescript
// Generated E2E Test for Logic Parity
// Ensures the modernized React component matches the legacy behavior
describe('Wafer Defect Logic Parity', () => {
  it('should correctly categorize severity based on micron threshold', () => {
    cy.visit('/modernized-wafer-analyzer');
    cy.get('[data-testid="defect-input"]').type('0.5µm');
    
    // Logic extracted from legacy behavior: 0.5µm triggers 'High' severity
    cy.get('[data-testid="severity-badge"]').should('contain', 'High');
  });
});

Built for the Regulated Nature of Silicon#

In the semiconductor world, security is non-negotiable. Whether you are dealing with ITAR regulations or SOC2 compliance, you cannot have your data leaking into a public LLM or a third-party cloud.

Replay is built for these environments:

• •On-Premise Deployment: Keep your source code and recordings behind your firewall.
• •SOC2 & HIPAA-Ready: Enterprise-grade security protocols.
• •Air-Gapped Support: For the most sensitive fab environments.

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Frequently Asked Questions#

How long does legacy extraction take with Replay?#

While a manual rewrite takes 18-24 months, Replay typically reduces this to 2-8 weeks. The extraction of a single complex screen—from video to documented React code—takes approximately 4 hours, compared to the industry average of 40 hours.

What about business logic preservation?#

Replay doesn't just "scrape" the UI. It monitors the data flow and network requests during the user session. This allows it to generate API contracts and E2E tests that verify the new system's logic against the legacy system's actual behavior, ensuring 100% parity.

Does Replay support air-gapped or on-premise environments?#

Yes. We understand that semiconductor IP is highly sensitive. Replay can be deployed entirely on-premise, ensuring that your recordings, codebases, and blueprints never leave your secure network.

Can Replay handle legacy terminal or desktop apps?#

Yes. Replay’s Visual Reverse Engineering is platform-agnostic. Whether your legacy software is a Java Swing desktop app, a mainframe terminal, or an early web app, if it can be displayed on a screen, Replay can extract it.

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