Modernizing Legacy EdTech Platforms: From Flash and Silverlight to React

Your EdTech platform is a ticking time bomb. While your competitors are shipping AI-driven personalized learning paths, your engineering team is likely playing "Software Archaeologist," trying to decompile obfuscated Silverlight DLLs or patch security holes in a browser-plugin architecture that the rest of the world abandoned years ago.

The $3.6 trillion global technical debt isn't just a number on a balance sheet; in EdTech, it’s the reason your churn rate is climbing and your "modernization" roadmap is a 24-month suicide mission. Most enterprise rewrites fail because they attempt to replicate 15 years of undocumented business logic from scratch.

The future of Silverlight to React migration isn't rewriting—it's understanding.

TL;DR: Manual legacy rewrites take 18-24 months and fail 70% of the time; Replay uses Visual Reverse Engineering to extract React components and logic from live workflows, cutting modernization time by 70%.

The Silverlight Trap: Why Your Rewrite is Stalling#

Silverlight was the gold standard for rich, stateful EdTech interactions—interactive quizzes, physics simulations, and complex student dashboards. But today, it’s a black box. 67% of these legacy systems lack any meaningful documentation. When you tell a stakeholder that a Silverlight to React migration will take two years, you aren't being conservative; you're acknowledging that you don't actually know how your own software works.

The traditional approach is "The Big Bang Rewrite." You hire a squad of consultants, they spend six months "discovering" requirements, and then they spend 18 months building a product that users hate because it missed the subtle business logic buried in the legacy UI.

The Cost of Manual Archaeology#

The math is brutal. Manual migration averages 40 hours per screen. With Replay, that drops to 4 hours. You aren't just saving money; you're reclaiming 90% of your engineering capacity to build features that actually drive ARR.

Moving from Black Box to Documented Codebase#

The primary hurdle in a Silverlight to React transition is the "state gap." Silverlight handled complex client-side state in a way that modern web standards didn't support until recently. If you try to manually map XAML to JSX, you will lose the intricate event handling that makes your educational tools functional.

Replay changes the paradigm. Instead of reading dead code, Replay records real user workflows. It watches how the data moves, how the UI reacts, and what the API contracts look like in practice. It turns a video of a user completing a lesson into a documented React component.

💰 ROI Insight: For a mid-sized EdTech platform with 100 core screens, a manual rewrite costs approximately $1.2M in engineering hours. Replay reduces this to under $150k while eliminating the "requirement gap" that causes post-release regressions.

Preserving Business Logic in React#

When migrating from Silverlight, the business logic is often "trapped" in the event triggers of the XAML. Replay’s AI Automation Suite identifies these patterns and generates clean, functional TypeScript code.

typescript
// Example: Replay-generated component preserving legacy quiz logic
// Source: Silverlight Assessment Module Workflow
import React, { useState, useEffect } from 'react';
import { z } from 'zod'; // Generated API Contract

// Replay identified this schema from network traffic during recording
const AssessmentSchema = z.object({
  questionId: z.string(),
  studentResponse: z.string(),
  attemptCount: z.number(),
  isFinalAttempt: z.boolean(),
});

type AssessmentData = z.infer<typeof AssessmentSchema>;

export const ModernAssessment: React.FC<{ initialData: AssessmentData }> = ({ initialData }) => {
  const [state, setState] = useState(initialData);

  // Business logic preserved: Silverlight 'OnSubmit' validation logic
  const handleSubmission = async (answer: string) => {
    if (state.isFinalAttempt && !answer) {
      console.warn("Legacy Logic Constraint: Final attempt requires non-null response");
      return;
    }
    
    // API Contract automatically generated by Replay
    const response = await fetch('/api/v1/assessment/submit', {
      method: 'POST',
      body: JSON.stringify({ ...state, studentResponse: answer }),
    });
    
    return response.json();
  };

  return (
    <div className="p-6 bg-white rounded-lg shadow-md">
      {/* Modern React UI mapped from legacy Visual Tree */}
      <h2 className="text-xl font-bold">Assessment Module</h2>
      <button 
        onClick={() => handleSubmission("A")}
        className="mt-4 px-4 py-2 bg-blue-600 text-white rounded"
      >
        Submit Response
      </button>
    </div>
  );
};

The 3-Step Modernization Workflow#

Stop guessing. Start recording. The Replay methodology moves you from "I think it works like this" to "I have the code to prove it."

Step 1: Visual Recording & Assessment#

Instead of interviews with subject matter experts (who have likely forgotten the edge cases), you record the actual application in use. Replay captures the DOM mutations, network calls, and state changes. This creates a "Source of Truth" based on reality, not outdated documentation.

Step 2: Extraction and Blueprinting#

Replay’s engine analyzes the recording to generate Blueprints. These aren't just screenshots; they are structural maps of your application.

• •Library: Automatically creates a Design System from your legacy UI.
• •Flows: Maps the architectural journey of a student or teacher.
• •API Contracts: Generates Swagger/OpenAPI specs from observed traffic.

Step 3: Automated Code Generation#

Using the AI Automation Suite, Replay converts these Blueprints into production-ready React components. It handles the heavy lifting of boilerplate, state management, and CSS-in-JS, leaving your senior architects to focus on high-level system design rather than component mapping.

⚠️ Warning: Most "automated conversion" tools fail because they try to translate code line-for-line. Replay succeeds because it translates intent and behavior into modern patterns.

Why Regulated Industries Trust Replay#

EdTech isn't just about UI; it's about data privacy. Whether you're dealing with COPPA in the US or GDPR in Europe, you cannot afford a "leaky" migration.

Replay is built for high-stakes environments:

• •SOC2 & HIPAA Ready: Your data remains secure throughout the extraction process.
• •On-Premise Available: For government or highly sensitive institutional data, Replay can run entirely within your firewall.
• •Technical Debt Audit: Replay doesn't just move code; it identifies redundant logic and dead endpoints, ensuring you don't migrate your mess.

Challenging the "Rewrite" Status Quo#

The "Big Bang" rewrite is a relic of the 2010s. It’s a low-trust, high-risk strategy that treats software like a building rather than a living organism. When you choose a Silverlight to React path, you are fundamentally dealing with a translation of institutional knowledge.

If your current modernization plan involves more than three months of "discovery," you are being billed for your own lack of documentation. Replay provides the "Documentation without archaeology" that allows you to skip the discovery phase and move straight to delivery.

typescript
// Replay generated E2E Test (Playwright) 
// Ensures parity between Legacy Silverlight and New React App
import { test, expect } from '@playwright/test';

test('Verification of Student Gradebook Parity', async ({ page }) => {
  await page.goto('/modern/gradebook');
  
  // Logic extracted from Replay recording of legacy system
  const gradeElement = page.locator('.grade-display');
  await expect(gradeElement).toContainText('A');
  
  // Verify API contract matches legacy behavior
  const [response] = await Promise.all([
    page.waitForResponse(res => res.url().includes('/api/v1/grades')),
    page.click('.refresh-button'),
  ]);
  
  expect(response.status()).toBe(200);
});

Frequently Asked Questions#

How long does a Silverlight to React extraction take?#

While a manual rewrite of a complex EdTech module typically takes 18 months, Replay users complete the same scope in 2 to 8 weeks. The speed comes from eliminating the manual mapping of UI to business logic.

What about business logic preservation?#

Replay records the actual execution of business logic. By observing the inputs, state changes, and outputs, it generates React code that mirrors the behavior of the legacy system, ensuring that edge cases—like specific grading rubrics or simulation parameters—are never lost.

Can Replay handle obfuscated or compiled code?#

Yes. Because Replay uses Visual Reverse Engineering, it doesn't need to read your source code to understand the application. It observes the rendered output and the network layer, making it the perfect tool for Silverlight, Flash, or older Java Applets where the source code may be lost or unreadable.

Does this replace my engineering team?#

No. It empowers them. Instead of spending 40 hours building a single screen, your engineers spend 4 hours refining the AI-generated output. It shifts their role from "manual laborers" to "system architects."

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