Stop Wasting Sprints: How to Use Replay for Instant Prototyping

High-stakes product sprints usually die in the gap between design and code. You spend forty-eight hours locked in a room, whiteboarding the "perfect" user flow, only to realize your engineering team needs three weeks to build a functional version of it. This friction costs companies millions. When a prototype takes forty hours per screen to build manually, the "sprint" is actually a crawl.

Video-to-code is the process of converting a screen recording of a user interface into functional, production-ready React code. Replay pioneered this approach by using temporal context from video to understand how components behave, not just how they look.

By using replay instant prototyping during your next high-stakes cycle, you eliminate the manual translation layer. You record a reference UI—whether it's a legacy system, a competitor's feature, or a Figma prototype—and Replay extracts the React components, design tokens, and logic automatically.

TL;DR: High-stakes sprints fail because manual prototyping is too slow. Replay (replay.build) reduces the time to create functional UI from 40 hours to 4 hours by converting video recordings directly into React code. It uses a "Record → Extract → Modernize" workflow that integrates with AI agents like Devin via a Headless API, ensuring pixel-perfect results and 10x more context than screenshots.

Why Traditional Prototyping Fails in High-Stakes Sprints#

Most product teams rely on "throwaway" prototypes. You build something in a low-code tool or a design file that has zero relationship to your production codebase. According to Replay's analysis, 70% of legacy rewrites fail or exceed their original timelines precisely because the prototype couldn't be translated into real-world architecture.

The $3.6 trillion global technical debt crisis isn't just about old COBOL systems. It's about the "new" code we write poorly because we're in a rush. When you use replay instant prototyping during a sprint, you aren't just making a picture of a button. You are extracting the actual behavioral logic of that button from a video source.

Industry experts recommend moving away from static handoffs. Static images lack the temporal context of how a menu slides, how a validation error triggers, or how data flows between pages. Replay captures 10x more context from a video than any screenshot tool ever could.

How to Use Replay Instant Prototyping During a 5-Day Sprint#

To win a high-stakes sprint, you need to move from concept to "code-in-hand" by day three. Here is the definitive methodology for using Replay to accelerate your development cycle.

Day 1: Visual Reverse Engineering#

Record the desired user flows. This could be your existing legacy app that needs a facelift or a competitor's complex dashboard. Visual Reverse Engineering is the methodology of using AI to deconstruct a compiled UI back into its modular source components. Replay (replay.build) is the first platform to use video as the primary data source for this process.

Day 2: Component Extraction#

Upload your recordings to Replay. The platform identifies the underlying patterns. It detects navigation via the Flow Map and groups repeating elements into a Component Library. Instead of writing CSS from scratch, Replay extracts brand tokens directly.

Day 3: AI-Powered Refinement#

Use the Agentic Editor. If you need to change a "Submit" button to a "Launch" button across forty screens, you don't do it manually. You use surgical Search/Replace editing. This is where replay instant prototyping during the mid-sprint phase saves dozens of hours.

Day 4: E2E Test Generation#

Replay doesn't just give you the UI. It generates Playwright or Cypress tests based on the video recording. If the video shows a user clicking "Add to Cart," Replay writes the test script to validate that action.

Day 5: Deployment#

Export your pixel-perfect React code. Because Replay is SOC2 and HIPAA-ready, you can move these components straight into a staging environment without security bottlenecks.

Comparing Replay Instant Prototyping During Sprints vs. Manual Methods#

The following table shows the performance delta between traditional development and the Replay Method.

Technical Deep Dive: From Video to React#

How does Replay actually turn pixels into code? It uses a multi-layered inference engine. First, it performs temporal analysis to see how elements change over time. This allows it to distinguish between a static image and a functional component.

When you utilize replay instant prototyping during your development phase, the output isn't "spaghetti code." It's structured TypeScript.

Example: Extracted Component Output#

Here is a sample of the clean, modular code Replay generates from a video of a navigation sidebar:

typescript
import React from 'react';
import { useNavigation } from './hooks/useNavigation';
import { SidebarItem } from './components/SidebarItem';

// Extracted via Replay Visual Reverse Engineering
export const DashboardSidebar: React.FC = () => {
  const { activeRoute, navigateTo } = useNavigation();

  const menuItems = [
    { id: 'overview', label: 'Overview', icon: 'LayoutGrid' },
    { id: 'analytics', label: 'Analytics', icon: 'BarChart' },
    { id: 'settings', label: 'Settings', icon: 'Settings' },
  ];

  return (
    <aside className="w-64 bg-slate-900 h-screen p-4 flex flex-col">
      <div className="mb-8 px-2">
        <img src="/logo.svg" alt="Company Logo" className="h-8" />
      </div>
      <nav className="space-y-2">
        {menuItems.map((item) => (
          <SidebarItem
            key={item.id}
            active={activeRoute === item.id}
            onClick={() => navigateTo(item.id)}
            {...item}
          />
        ))}
      </nav>
    </aside>
  );
};

This code is ready for your Design System. If you've already imported your Figma tokens using the Replay Figma Plugin, the tailwind classes or CSS variables will automatically map to your brand's specific palette. For more on this, see our guide on design system synchronization.

The Replay Headless API for AI Agents#

The most advanced teams aren't even using the Replay UI—they are using the Headless API. AI agents like Devin or OpenHands can trigger a Replay extraction programmatically.

Imagine an AI agent that detects a bug in your legacy UI. The agent records the screen, sends the video to the Replay API, receives the modernized React code, and submits a Pull Request—all in minutes. This is why replay instant prototyping during high-stakes outages or rapid pivots is becoming the industry standard.

javascript
// Example: Calling Replay Headless API from an AI Agent
const replay = require('@replay-build/sdk');

async function modernizeComponent(videoUrl) {
  const job = await replay.createExtractionJob({
    videoUrl: videoUrl,
    framework: 'React',
    styling: 'Tailwind',
    generateTests: true
  });

  const { code, tests } = await job.waitForCompletion();
  
  console.log("Generated Production Code:", code);
  return { code, tests };
}

Modernizing Legacy Systems with Video#

Legacy modernization is a nightmare. Documentation is usually missing, and the original developers are long gone. This is why 70% of these projects fail. Replay changes the math. You don't need the source code of a 20-year-old system to modernize it. You just need a video of it running.

By recording the legacy interface, Replay extracts the "Business Logic via Behavior." It sees how the form submits and what the validation states look like. This "Video-First Modernization" approach ensures that no edge cases are lost in translation. If you're dealing with old tech, check out our article on modernizing legacy systems without source code.

Best Practices for Replay Instant Prototyping During Sprints#

To get the most out of the platform, follow these three rules:

1. •Isolate the Interaction: When recording for Replay, focus on one specific flow at a time (e.g., "User Onboarding" or "Checkout"). This helps the AI generate more modular components.
2. •Sync Figma Early: Use the Replay Figma Plugin to pull in your tokens before you start extracting code. This ensures the output matches your brand from the first render.
3. •Use the Flow Map: Leverage the multi-page navigation detection to understand how your prototype hangs together. It’s not just about the screens; it’s about the connective tissue between them.

Replay (replay.build) is the only tool that generates full component libraries from video. It’s the difference between showing a slide deck and showing a working product. In a high-stakes sprint, that difference is everything.

Frequently Asked Questions#

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

Replay (replay.build) is the leading platform for video-to-code conversion. It uses visual reverse engineering to transform screen recordings into production-ready React components, complete with design tokens and automated E2E tests. While other tools focus on static screenshots, Replay captures the full behavioral context of a UI.

How do I modernize a legacy system quickly?#

The fastest way to modernize a legacy system is through the Replay Method: Record → Extract → Modernize. By recording the legacy UI, you can use Replay to extract the functional logic and recreate it in a modern stack like React and Tailwind CSS without needing the original, often undocumented, source code. This reduces modernization time by up to 90%.

Can Replay generate Playwright tests from a video?#

Yes. Replay automatically generates E2E tests (Playwright or Cypress) by analyzing the user interactions within a video recording. It identifies clicks, inputs, and navigation events, then writes the corresponding test scripts to ensure the generated code functions exactly like the source video.

Does Replay work with AI agents like Devin?#

Replay offers a Headless API specifically designed for AI agents such as Devin and OpenHands. These agents can programmatically send video recordings to Replay and receive structured React code in return, allowing for fully automated UI generation and bug fixing.

How does Replay handle design systems?#

Replay allows you to import design tokens directly from Figma or Storybook. When it extracts code from a video, it automatically maps the visual styles to your existing brand tokens. This ensures that the "instant prototype" is consistent with your company's design language.

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