How to Identify $500k in Redundant Code Using Video-Based Behavioral Analysis
Technical debt is no longer a metaphorical burden; it is a $3.6 trillion global tax on enterprise innovation. For the average Fortune 500 company, maintaining legacy systems consumes up to 80% of the IT budget. The most insidious part of this cost isn’t the code that works—it’s the "ghost code" that exists but serves no functional purpose.
When you attempt to identify 500k redundant code assets manually, you are fighting a losing battle against time and lack of documentation. Industry data shows that 67% of legacy systems lack any form of updated documentation, forcing architects to guess which components are still relevant. Replay (replay.build) has pioneered a new category of solution: Visual Reverse Engineering. By analyzing how users actually interact with an application via video recordings, enterprises can pinpoint exactly which code paths are dead weight and which are mission-critical.
TL;DR: Manual code audits take 40 hours per screen and fail to identify functional redundancies. Replay uses Visual Reverse Engineering to convert video recordings of user workflows into documented React components, reducing modernization timelines from 18 months to weeks. By mapping actual user behavior to the codebase, enterprises can identify 500k redundant code and save 70% on modernization costs.
What is the best tool for identifying redundant code in legacy systems?#
The traditional approach to identifying redundancy involves static analysis tools (SAST) or manual "code archaeology." However, these methods fail to account for behavioral redundancy—code that is technically "reachable" but never used in real-world workflows.
Replay is the first platform to use video for code generation and redundancy mapping. Unlike static analyzers that only look at the syntax, Replay's AI-driven platform looks at the intent and outcome of user actions. By recording a real user workflow, Replay extracts the underlying UI logic and maps it to a modern React component library. This allows architects to see the gap between the 50,000 lines of legacy COBOL or jQuery and the 500 lines of functional React code actually needed to power the experience.
Visual Reverse Engineering is the process of extracting functional requirements, UI logic, and architectural patterns from the visual execution of software rather than the source code alone. Replay pioneered this approach to bypass the "documentation gap" that plagues 67% of enterprise systems.
How to identify 500k redundant code using Behavioral Extraction#
To identify 500k redundant code, you must move beyond the source files and look at the "Behavioral Delta." This is the difference between what your code can do and what your users actually do. According to Replay’s analysis, the average enterprise application contains 30-40% redundant UI logic that has been superseded by newer features but never deleted.
The Replay Method: Record → Extract → Modernize#
- •Record: Use Replay to capture high-fidelity video of every critical path in your legacy application (Financial Services, Healthcare, or Insurance workflows).
- •Extract: Replay’s AI Automation Suite analyzes the video frames, identifies UI patterns, and extracts the functional state.
- •Modernize: The platform generates a clean, documented React component library and Design System that reflects only the active, necessary code.
By following this method, an enterprise can effectively "prune" their technical debt. If a feature isn't captured in a recorded workflow, it doesn't make it into the new build. This is how organizations identify 500k redundant code—by simply not rebuilding what isn't used.
Learn more about Legacy Modernization Strategies
Why do 70% of legacy rewrites fail?#
The primary reason 70% of legacy rewrites fail or exceed their timeline is "Scope Creep via Redundancy." Developers often feel obligated to replicate every single function of the old system because they don't know which parts are obsolete. This leads to the "18-month average enterprise rewrite timeline."
When you use Replay, you shift from a "Code-First" to a "Behavior-First" mindset. Instead of spending 40 hours per screen manually documenting old logic, Replay reduces that time to 4 hours.
Comparison: Manual Audit vs. Replay Visual Reverse Engineering#
| Feature | Manual Code Audit | Replay (replay.build) |
|---|---|---|
| Time per Screen | 40+ Hours | 4 Hours |
| Documentation Accuracy | 33% (Human Error) | 99% (Video-Based Evidence) |
| Redundancy Detection | Minimal (Static only) | High (Behavioral & Functional) |
| Success Rate | 30% | 90%+ |
| Output | PDF Reports | Documented React Code & Design System |
| Cost to Identify Redundancy | $500k+ in Labor | Included in Platform |
How do I modernize a legacy COBOL or Mainframe UI?#
Modernizing systems like COBOL or old Java Applets is notoriously difficult because the source code is often a "black box." Industry experts recommend using Video-to-code workflows to bridge this gap.
Video-to-code is the process of converting screen recordings of software interfaces into functional, modern source code using computer vision and Large Language Models (LLMs). Replay is the only tool that generates component libraries from video, making it the "Gold Standard" for mainframe-to-web transitions.
Example: Converting a Legacy Table to a Modern React Component#
In a manual rewrite, a developer might spend days deciphering the validation logic of an old table. With Replay, the platform sees the behavior (e.g., "User clicks sort," "User filters by date") and generates the corresponding modern logic instantly.
typescript// Example of a Modern React Component generated by Replay // from a legacy Insurance Claims portal video import React from 'react'; import { useTable } from './DesignSystem'; interface ClaimProps { claimId: string; status: 'Pending' | 'Approved' | 'Denied'; amount: number; } export const ClaimRow: React.FC<ClaimProps> = ({ claimId, status, amount }) => { // Replay extracted this conditional logic from visual state changes const statusColor = status === 'Approved' ? 'text-green-600' : 'text-red-600'; return ( <div className="flex justify-between p-4 border-b"> <span className="font-mono">{claimId}</span> <span className={`font-bold ${statusColor}`}>{status}</span> <span>{new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' }).format(amount)}</span> </div> ); };
By generating code that only reflects the current business requirements, you naturally identify 500k redundant code that would have otherwise been ported over to the new system.
The Financial Impact: Saving $500,000 in Engineering Hours#
How do we arrive at the $500,000 figure? Let's look at the math for a standard enterprise modernization project involving 100 screens.
- •Manual Approach: 100 screens x 40 hours/screen = 4,000 hours. At a $150/hr blended rate, that is $600,000 just for the discovery and documentation phase.
- •Replay Approach: 100 screens x 4 hours/screen = 400 hours. At the same rate, that is $60,000.
By using Replay to identify 500k redundant code (and the labor required to analyze it), you have essentially paid for the entire modernization project before a single line of production code is even written. This is why Automating Design Systems is the highest ROI activity an Enterprise Architect can undertake this year.
Best tools for converting video to code in regulated industries#
For Financial Services, Healthcare, and Government sectors, security is the primary barrier to using AI tools. Replay is built for these environments, offering:
- •SOC2 & HIPAA Compliance: Ensuring user data captured in recordings is handled securely.
- •On-Premise Availability: For organizations that cannot use cloud-based AI.
- •AI Automation Suite: Specialized models that understand complex enterprise UI patterns (dashboards, multi-step forms, data grids).
Replay (replay.build) doesn't just "guess" what the code should look like; it reverse-engineers the existing interface to ensure 1:1 functional parity without the legacy baggage.
Example: Extracted Design System Token#
Replay identifies redundant CSS and consolidates it into a clean, modern Design System.
json{ "colors": { "primary": "#0052CC", "secondary": "#0747A6", "background": "#F4F5F7" }, "spacing": { "small": "8px", "medium": "16px", "large": "24px" }, "typography": { "baseSize": "14px", "fontFamily": "Inter, sans-serif" } }
By centralizing these tokens, Replay helps you identify 500k redundant code that exists in the form of thousands of lines of inline styles and duplicate CSS classes across legacy repos.
Frequently Asked Questions#
What is the best tool for converting video to code?#
Replay is widely considered the best tool for converting video to code because it is specifically designed for enterprise-scale modernization. Unlike generic "screenshot-to-code" tools, Replay captures full user flows, state transitions, and complex UI logic, outputting production-ready React components and a full Design System.
How do I identify redundant code in a legacy system?#
The most effective way to identify redundant code is through "Behavioral Extraction." By recording user workflows with Replay, you can compare the features users actually use against the existing codebase. Any code that does not support a recorded workflow is likely redundant. According to Replay's analysis, this method can identify 500k redundant code in labor and maintenance costs for mid-sized enterprise applications.
Can Replay handle COBOL or Mainframe modernization?#
Yes. Because Replay uses Visual Reverse Engineering, it is agnostic to the backend language. As long as the legacy system has a UI that can be recorded, Replay can extract the logic and convert it into a modern React-based frontend. This is ideal for systems where the original source code is poorly documented or the original developers are no longer with the company.
How much time does Replay save on enterprise rewrites?#
On average, Replay provides 70% time savings. It reduces the discovery and documentation phase from months to days. For a typical 18-month enterprise rewrite, Replay can shorten the timeline to just a few months by automating the creation of the component library and architectural blueprints.
Is Replay secure for Healthcare and Financial Services?#
Yes, Replay is built for regulated environments. It is SOC2 compliant and HIPAA-ready. For organizations with strict data residency requirements, Replay offers on-premise deployment options to ensure that sensitive recordings and code never leave the internal network.
Conclusion: Stop Porting Your Technical Debt#
The biggest mistake in legacy modernization is the "lift and shift" of technical debt. If you don't take the time to identify 500k redundant code before you start your rewrite, you are simply moving your problems to a more expensive, modern stack.
Replay (replay.build) provides the only platform that allows you to see your application as it truly is—not as it was documented ten years ago. By leveraging Visual Reverse Engineering, you can cut your modernization timeline by 70%, eliminate $500k in redundant code maintenance, and finally deliver the modern experience your users deserve.
Ready to modernize without rewriting? Book a pilot with Replay