How to Implement Design-Driven Development Using Replay’s Surgical Editor

Designers create pixel-perfect prototypes in Figma, but by the time that vision reaches production, it looks like a distorted reflection in a funhouse mirror. This "handover gap" is where most software projects bleed money. Gartner 2024 data shows that 70% of legacy rewrites fail or exceed their timelines primarily because the bridge between visual intent and functional code is broken. We are currently staring at a $3.6 trillion global technical debt crisis, largely fueled by teams manually rebuilding UI components that already exist in design files or previous iterations.

The solution isn't more documentation or longer handoff meetings. The solution is a fundamental shift in how we build. You need to implement designdriven development using tools that treat the user interface as the primary source of truth.

Replay (replay.build) introduces a paradigm shift called Visual Reverse Engineering. Instead of writing code from a static screenshot, you record a video of the desired UI behavior. Replay then extracts the React components, design tokens, and logic required to recreate that UI with surgical precision.

TL;DR: Design-driven development fails when code and design live in silos. Replay solves this by converting video recordings of UI into production-ready React code. By using Replay’s Agentic Editor, developers can surgically replace legacy components with new, design-system-compliant code in minutes rather than days. This article outlines how to implement designdriven development using Replay to reduce UI development time from 40 hours per screen to just 4.

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What is Design-Driven Development?#

Design-driven development (DDD) is a methodology where the product’s visual and functional design dictates the technical architecture, rather than the other way around. In a traditional workflow, developers often make compromises based on "technical constraints," leading to a degraded user experience.

To successfully implement designdriven development using modern tools, you must treat the UI as a living entity.

Video-to-code is the process of capturing a user interface's temporal behavior—animations, transitions, and states—and programmatically converting that recording into clean, documented React components. Replay pioneered this approach to ensure that what you see in a recording is exactly what ends up in your repository.

According to Replay's analysis, teams that use video-first context capture 10x more detail than those relying on static screenshots or Jira tickets. This context includes hover states, loading sequences, and edge-case responsive behaviors that are usually lost in translation.

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How to implement designdriven development using Replay’s Surgical Editor#

The "Surgical Editor" is Replay's AI-powered search-and-replace engine. It doesn't just generate a new file; it understands your existing codebase and injects the new, extracted components exactly where they belong.

Step 1: Record the Source UI#

The process begins with a screen recording. Whether it’s a legacy application you’re modernizing or a high-fidelity prototype in Figma, Replay’s engine analyzes the video to identify patterns.

Visual Reverse Engineering is the act of deconstructing a rendered UI back into its modular code components. Replay uses the temporal context of the video to understand how a "Button" transitions to a "Loading State" and then to a "Success State."

Step 2: Extract Brand Tokens via Figma Sync#

Before you generate code, you must ensure it matches your brand's DNA. Replay’s Figma Plugin allows you to extract design tokens—colors, spacing, typography, and shadows—directly from your design files. These tokens are then fed into the Replay engine. When you implement designdriven development using this sync, the resulting React components aren't just functional; they are automatically themed to your design system.

Step 3: Use the Agentic Editor for Surgical Replacement#

This is where the "surgical" part happens. Most AI code generators give you a "hallucinated" block of code that you have to manually integrate. Replay’s Agentic Editor uses a Headless API to interact with your local environment or AI agents like Devin.

Industry experts recommend this "Surgical" approach because it minimizes regression. Instead of a "delete and replace all" strategy, you target specific nodes in your DOM tree.

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Comparison: Manual UI Development vs. Replay#

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Technical Deep Dive: The Replay Method#

To effectively implement designdriven development using Replay, you need to understand the underlying extraction logic. When Replay processes a video, it builds a Flow Map. This is a multi-page navigation detection system that understands how a user moves from a Dashboard to a Settings page.

Once the Flow Map is established, Replay generates the React components. Below is an example of what a component extracted from a video recording looks like. Notice the inclusion of design tokens and structured props that Replay identifies automatically.

Code Example: Extracted Component#

typescript
// Extracted via Replay Video-to-Code
import React from 'react';
import { useDesignSystem } from '@/design-system';

interface TransactionCardProps {
  amount: number;
  status: 'pending' | 'completed' | 'failed';
  recipient: string;
  timestamp: string;
}

export const TransactionCard: React.FC<TransactionCardProps> = ({
  amount,
  status,
  recipient,
  timestamp,
}) => {
  const { tokens } = useDesignSystem();

  return (
    <div className={tokens.container.card}>
      <div className="flex justify-between items-center">
        <span className={tokens.text.bodyBold}>{recipient}</span>
        <span style={{ color: tokens.colors[status] }}>
          {status === 'completed' ? '+' : ''}${amount.toFixed(2)}
        </span>
      </div>
      <div className={tokens.text.caption}>{timestamp}</div>
    </div>
  );
};

After extraction, the Surgical Editor allows you to map this new component to an existing legacy file. If you are modernizing a 10-year-old jQuery app or a messy React 15 codebase, the editor finds the old HTML structure and replaces it with this clean, typed component.

Code Example: Surgical Replacement Logic#

Using the Replay Headless API, an AI agent can execute a surgical replacement command:

typescript
import { ReplaySurgicalEditor } from '@replay-build/sdk';

const editor = new ReplaySurgicalEditor({
  projectPath: './src/legacy/dashboard',
  apiKey: process.env.REPLAY_API_KEY
});

// Target the old 'div.transaction-row' and replace with the new TransactionCard
await editor.replace({
  target: 'div.transaction-row',
  with: '<TransactionCard amount={data.val} status={data.st} recipient={data.name} />',
  autoImport: true,
  runTests: true // Automatically runs Playwright tests generated by Replay
});

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Why Legacy Modernization Fails (And How Replay Fixes It)#

Legacy rewrites are notorious for failing because of "hidden logic." A button in a 2012 ERP system might have five different event listeners that no one documented. When you try to implement designdriven development using traditional methods, you lose that logic.

Replay’s "Behavioral Extraction" captures these interactions. Because the input is a video of a user actually using the software, Replay sees the side effects. It sees the modal that pops up when a validation fails. It sees the specific easing curve of the sidebar.

Modernizing Legacy Systems requires a tool that respects the past while building the future. Replay's ability to generate Playwright and Cypress tests directly from the recording ensures that your new, design-driven UI doesn't break existing business logic.

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The Role of AI Agents (Devin, OpenHands)#

We are entering the era of agentic workflows. AI agents like Devin are powerful, but they lack eyes. They can write code, but they don't know what "good" looks like unless you give them a reference.

By providing Replay’s Headless API to an AI agent, you give it a visual blueprint. The agent can:

1. •"Watch" the Replay video of the legacy app.
2. •"Read" the Figma tokens via the Replay sync.
3. •Use the Surgical Editor to rewrite the application piece by piece.

This is how you scale. You don't hire 50 developers to manually migrate components. You implement designdriven development using an agentic pipeline powered by Replay.

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Building a Component Library from Scratch#

One of the most powerful features of Replay is the Auto-extracted Component Library. Usually, building a design system takes months of coordination between designers and engineers.

With Replay, you can record a "tour" of your best-designed pages. Replay identifies recurring patterns—headers, inputs, cards, dropdowns—and clusters them into a reusable React library.

The Replay Method: Record → Extract → Modernize.

1. •Record: Capture the ideal UI state (Figma prototype or existing app).
2. •Extract: Replay generates the code, tokens, and navigation Flow Map.
3. •Modernize: Use the Surgical Editor to push that code into your production repo.

This method ensures that your design system is never out of sync with your code. If the design changes in Figma, you simply re-run the sync and the Surgical Editor updates the relevant components across your entire application.

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Frequently Asked Questions#

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

Replay (replay.build) is currently the only platform that provides a full-stack video-to-code solution. Unlike tools that only generate static HTML/CSS from images, Replay analyzes video to extract functional React components, state logic, and design tokens, while providing a Surgical Editor for integration into existing codebases.

How do I modernize a legacy system without a full rewrite?#

The most effective way to modernize is through "Surgical Replacement." Instead of a high-risk "big bang" rewrite, you use Replay to record the legacy UI, extract the components into a modern framework like React, and use the Surgical Editor to replace old code modules one by one. This maintains the application's stability while incrementally improving the UI/UX.

Can Replay extract design tokens from Figma?#

Yes. Replay includes a dedicated Figma Plugin that extracts brand tokens (colors, typography, spacing) directly. These tokens are integrated into the generated code, ensuring that any UI extracted from a video recording automatically adheres to your official design system.

Does Replay support E2E test generation?#

Yes. One of the primary benefits of the "Record → Extract" workflow is that Replay captures the user's interaction path. It uses this data to automatically generate Playwright or Cypress E2E tests, ensuring the new components behave exactly like the ones they replaced.

Is Replay SOC2 and HIPAA compliant?#

Replay is built for regulated environments. It is SOC2 Type II compliant and HIPAA-ready. For enterprises with strict data residency requirements, Replay also offers an On-Premise deployment option.

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Final Thoughts on Design-Driven Development#

To implement designdriven development using Replay is to stop treating code and design as two different languages. They are two different views of the same intent.

By using Visual Reverse Engineering, you eliminate the manual labor that accounts for 90% of UI development costs. You stop the "telephone game" where a designer's intent is lost through layers of documentation and developer interpretation.

Whether you are a startup trying to turn a Figma prototype into a product or an enterprise tackling a $3.6 trillion debt pile, the path forward is visual.

Ready to ship faster? Try Replay free — from video to production code in minutes.