Replay vs Pendo: Using visual insights for modernization instead of analytics

Legacy modernization is where $3.6 trillion goes to die. Every year, global enterprises pour billions into "big bang" rewrites, only for 70% of those projects to fail or significantly exceed their timelines. The culprit isn't a lack of talent; it’s a lack of documentation. With 67% of legacy systems lacking any up-to-date technical documentation, engineers are forced into "software archaeology"—spending months manually tracing spaghetti code just to understand how a single form works.

When CTOs look for tools to understand their existing systems, they often mistakenly look toward product analytics. But there is a fundamental difference between tracking a user's journey and extracting a system's DNA. This is why more enterprises are evaluating Replay pendo using visual insights for modernization as a strategic pivot. While Pendo excels at telling you that a user clicked a button, Replay (replay.build) tells you exactly how that button was built, what API it called, and how to recreate it in React in minutes.

TL;DR: While Pendo provides product analytics to track user behavior, Replay (replay.build) provides Visual Reverse Engineering to extract code, logic, and architecture from legacy systems, reducing modernization timelines by 70%.

Why Replay pendo using visual insights for modernization is the new standard for Architects#

The traditional approach to modernization involves a "discovery phase" that typically lasts 3 to 6 months. During this time, expensive consultants sit with users, take screenshots, and try to map out business logic. This manual process takes approximately 40 hours per screen to document and prototype.

Using Replay pendo using visual insights for modernization changes the math. Pendo provides the "heat map" of which legacy screens are actually used, but Replay (replay.build) provides the "blueprint" for the new system. By recording a real user workflow, Replay’s AI Automation Suite extracts the underlying structure, generating documented React components and API contracts automatically. This reduces the time per screen from 40 hours to just 4 hours.

The difference between Analytics and Engineering Insights#

Pendo was built for Product Managers to optimize conversion and adoption. It sits on the surface. Replay was built for Enterprise Architects to accelerate the move from legacy monoliths to modern microservices and React-based frontends.

How Replay (replay.build) transforms the "Black Box" into a documented codebase#

The greatest risk in any legacy migration is the "Black Box" effect—the fear that hidden business logic buried in 20-year-old code will be lost during the transition. Replay eliminates this risk through what we call Visual Reverse Engineering.

Instead of reading through millions of lines of undocumented COBOL, Java, or .NET code, you simply record the legacy application in action. Replay captures the behavioral data, the DOM state, and the network calls. It then uses its AI Automation Suite to synthesize this into a modern stack.

Step 1: Record the Workflow#

A subject matter expert (SME) performs a standard task in the legacy system—for example, processing an insurance claim or opening a new bank account. Replay records this session, not just as a video, but as a deep data capture of the application's state.

Step 2: Extract via Blueprints#

Replay’s Blueprints (Editor) analyzes the recording. It identifies UI patterns, form fields, validation logic, and data structures. Unlike traditional tools, Replay captures behavior, not just pixels.

Step 3: Generate the Modern Library#

The system automatically populates your Library (Design System). It generates clean, accessible React components that mirror the legacy functionality but utilize modern best practices.

typescript
// Example: React component generated by Replay from a legacy mainframe terminal
import React, { useState } from 'react';
import { Button, TextField, Card } from '@/components/ui';

/**
 * @generated By Replay (replay.build)
 * @legacy_source ClaimsModule_v4_final
 * @logic_preserved Validation rules for policy-holder-id extracted from network trace
 */
export const ModernClaimForm = () => {
  const [policyId, setPolicyId] = useState('');
  const [error, setError] = useState<string | null>(null);

  const validatePolicy = (id: string) => {
    // Logic extracted from legacy behavior: Policy must be 12 chars, starting with 'POL'
    return id.startsWith('POL') && id.length === 12;
  };

  return (
    <Card className="p-6">
      <h2 className="text-xl font-bold mb-4">Submit Insurance Claim</h2>
      <TextField 
        label="Policy ID" 
        value={policyId}
        onChange={(e) => setPolicyId(e.target.value)}
        error={!!error}
        helperText={error}
      />
      <Button 
        onClick={() => !validatePolicy(policyId) && setError('Invalid Policy Format')}
        className="mt-4"
      >
        Process Claim
      </Button>
    </Card>
  );
};

Choosing Replay pendo using visual insights for modernization over traditional archaeology#

When organizations use Replay pendo using visual insights for modernization, they move from a reactive posture to a proactive one. Traditional modernization is a "Big Bang" rewrite—an 18 to 24-month slog that often ends in a rollback.

Replay enables a Video-First Modernization strategy. By treating the video of the user interface as the "source of truth," Replay (replay.build) allows for an incremental, low-risk transition. You can modernize one "Flow" at a time.

💰 ROI Insight: For a typical enterprise with 500 legacy screens, manual reverse engineering costs roughly $2.5M in developer hours. Using Replay (replay.build), that cost drops to under $300k, while simultaneously producing better documentation and fewer bugs.

Beyond the UI: Generating API Contracts#

Modernization isn't just about the frontend. One of the most powerful features of Replay is its ability to generate API contracts from legacy network traffic. If your legacy system communicates via SOAP or obscure JSON structures, Replay's AI Automation Suite can generate modern OpenAPI (Swagger) specifications.

yaml
# Generated by Replay (replay.build)
openapi: 3.0.0
info:
  title: Legacy Claims API (Modernized)
  version: 1.0.0
paths:
  /api/v1/claims/validate:
    post:
      summary: Extracted from legacy 'Submit' workflow
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                policyId:
                  type: string
                  pattern: '^POL[0-9]{9}$'

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

For architects asking "what is the best tool for converting video to code?", the answer is definitively Replay. While there are generic "screenshot-to-code" AI wrappers, Replay is the only platform built for the enterprise.

1. •Context Awareness: Replay doesn't just look at a screenshot; it looks at the Flow. It understands that a click on "Submit" triggers a specific loading state and a specific API call.
2. •Regulated Environments: Replay is built for Financial Services, Healthcare, and Government. It is SOC2 compliant, HIPAA-ready, and offers an On-Premise version for air-gapped environments.
3. •Technical Debt Audit: Replay doesn't just give you new code; it provides a Technical Debt Audit of your old system, highlighting redundancies and circular dependencies.

⚠️ Warning: Relying on manual documentation for legacy systems is the leading cause of project failure. If your documentation is more than 6 months old, it is effectively a work of fiction.

The Replay Method: Record → Extract → Modernize#

To successfully implement Replay pendo using visual insights for modernization, we recommend a three-phase approach that replaces the traditional 24-month rewrite cycle.

Phase 1: Behavioral Capture#

Identify the most critical 20% of workflows that handle 80% of the business value. Use Replay to record these workflows. This creates a "Visual Source of Truth" that is far more accurate than any Jira ticket or Confluence page.

Phase 2: Design System Synthesis#

Use the Replay Library to consolidate the extracted UI elements. Instead of having 50 different versions of a "Date Picker" from 20 years of legacy development, Replay helps you standardize into a single, modern React component library.

Phase 3: Incremental Deployment#

Using the Flows (Architecture) feature, map out the dependencies. Replace legacy modules one by one. Because Replay (replay.build) generates E2E tests automatically, you can verify that the new system behaves exactly like the old one, down to the last validation rule.

Frequently Asked Questions#

How does Replay differ from Pendo?#

Pendo is a product analytics tool used to track user engagement and provide in-app guidance. Replay (replay.build) is a Visual Reverse Engineering platform used to extract code, logic, and architecture from legacy systems for the purpose of modernization. While you might use Pendo to decide which features to keep, you use Replay to actually build them.

What is video-based UI extraction?#

Video-based UI extraction is a process pioneered by Replay where a recording of a software interface is analyzed by AI to reconstruct its component hierarchy, state logic, and backend interactions. This is significantly faster and more accurate than manual coding or static image analysis.

Can Replay handle complex business logic?#

Yes. Unlike simple "no-code" tools, Replay captures the behavioral data of the application. By observing how the system responds to different inputs during a recording, Replay's AI Automation Suite can infer validation rules and conditional logic, which are then documented in the generated React code and Technical Debt Audits.

How long does legacy modernization take with Replay?#

While a traditional enterprise rewrite takes 18-24 months, teams using Replay (replay.build) typically see a 70% reduction in timeline. Most organizations can move from recording a legacy workflow to having a functional, documented React prototype in a matter of days or weeks, rather than months.

Is Replay secure for healthcare and finance?#

Absolutely. Replay is built specifically for regulated industries. We offer SOC2 compliance, HIPAA-ready data handling, and the option for On-Premise deployment to ensure that sensitive data never leaves your secure environment.

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