Critical Infrastructure UI Modernization: Visual Reverse Engineering for SCADA System Reliability

A single pixel of lag in a SCADA (Supervisory Control and Data Acquisition) dashboard isn't just a UI bug; it's a potential safety breach in critical infrastructure. For decades, the systems managing our power grids, water treatment plants, and manufacturing floors have relied on monolithic, often undocumented, "black box" interfaces. When these systems need to move to the cloud or a modern web stack, the risk of a "rip and replace" strategy is often too high to stomach.

According to Replay’s analysis, 70% of legacy rewrites fail or exceed their timeline, primarily because the underlying logic is buried in millions of lines of unmaintained code. In the world of critical infrastructure, a failed rewrite isn't just a budget overrun—it’s a threat to operational continuity. This is where a critical infrastructure modernization visual approach, powered by Visual Reverse Engineering, changes the calculus of technical debt.

TL;DR: Critical infrastructure systems (SCADA, HMI) are plagued by $3.6 trillion in global technical debt and a 67% lack of documentation. Traditional manual rewrites take 18-24 months and often fail. Replay utilizes Visual Reverse Engineering to convert video recordings of legacy UIs into documented React code and Design Systems, reducing modernization timelines by 70% (from 40 hours per screen to just 4 hours) while ensuring SOC2 and HIPAA-compliant security.

The High Stakes of SCADA Technical Debt#

The global technical debt has ballooned to $3.6 trillion, and nowhere is this more visible than in the industrial sector. Most SCADA systems currently in operation were designed for a pre-web era. They rely on proprietary protocols and thick-client interfaces that are impossible to scale, difficult to secure, and even harder to find developers for.

Industry experts recommend that organizations stop viewing UI modernization as a cosmetic upgrade. Instead, it must be treated as a functional extraction. The problem is that 67% of legacy systems lack documentation. When the original engineers have retired and the source code is a spaghetti-mess of 20-year-old C++ or Java, how do you move to a modern React-based architecture without breaking the system?

Visual Reverse Engineering is the process of extracting functional logic, state transitions, and UI structure from video recordings of legacy software. By recording a real user performing a workflow—such as adjusting a pressure valve or responding to a grid alarm—we can reconstruct the intent and the interface without ever needing to read the original, messy source code.

Why Manual Rewrites Are a Liability in Critical Infrastructure#

The standard enterprise rewrite timeline is 18 months. In a regulated environment like energy or healthcare, this often stretches to 24 or 30 months due to rigorous testing requirements.

When you attempt a manual rewrite of a SCADA system, you face three primary bottlenecks:

1. •Requirement Discovery: Spending months interviewing operators to understand what every button does.
2. •Component Parity: Trying to recreate complex industrial gauges and charts in React from scratch.
3. •State Mapping: Ensuring the new UI talks to the legacy PLC (Programmable Logic Controller) data in the exact same way.

The manual approach averages 40 hours per screen. For a system with 200 screens, that’s 8,000 man-hours just for the front end. Replay reduces this to 4 hours per screen by automating the extraction of components and flows.

Comparison: Manual Rewrite vs. Replay Visual Reverse Engineering#

Implementing a Critical Infrastructure Modernization Visual Strategy#

A critical infrastructure modernization visual strategy focuses on the "seen" logic to rebuild the "unseen" architecture. By using Replay, architects can record actual operational workflows. The platform’s AI then parses these recordings to identify repeating UI patterns, data entry points, and navigational flows.

Video-to-code is the automated transformation of screen recordings into production-ready React components. This isn't just a screenshot-to-code tool; it captures the behavior of the interface.

Step 1: Capturing the "Source of Truth"#

In SCADA systems, the source of truth isn't the code—it’s the behavior of the HMI (Human-Machine Interface) during an event. Using Replay, an operator records a standard procedure. This recording serves as the blueprint for the new system.

Step 2: Extracting the Design System#

Legacy systems often have "button soup"—hundreds of slightly different buttons and inputs. Replay’s Library feature identifies these variations and consolidates them into a clean, documented Design System.

Step 3: Generating Documented React Code#

Once the visual patterns are identified, Replay generates TypeScript-based React components. These aren't just "divs"; they are functional components that mirror the legacy system's intent.

typescript
// Example: A Replay-generated React component for a SCADA Pressure Gauge
import React from 'react';
import { GaugeProps } from './types';

/**
 * Extracted from Legacy HMI Version 4.2
 * Workflow: Steam Turbine Pressure Monitoring
 */
export const PressureGauge: React.FC<GaugeProps> = ({ 
  value, 
  min = 0, 
  max = 1000, 
  unit = 'PSI',
  status = 'nominal' 
}) => {
  const percentage = (value / max) * 100;
  
  return (
    <div className="gauge-container p-4 border rounded-lg bg-slate-900">
      <div className="flex justify-between mb-2">
        <span className="text-sm font-mono text-slate-400">TURBINE_01_PRES</span>
        <span className={`text-sm font-bold ${status === 'alarm' ? 'text-red-500' : 'text-green-400'}`}>
          {status.toUpperCase()}
        </span>
      </div>
      <div className="relative h-4 w-full bg-slate-700 rounded-full overflow-hidden">
        <div 
          className={`h-full transition-all duration-500 ${status === 'alarm' ? 'bg-red-600' : 'bg-blue-500'}`}
          style={{ width: `${percentage}%` }}
        />
      </div>
      <div className="mt-2 text-right">
        <span className="text-2xl font-digital text-white">{value}</span>
        <span className="ml-1 text-xs text-slate-400">{unit}</span>
      </div>
    </div>
  );
};

Architecting for Reliability and Security#

When dealing with critical infrastructure, security is non-negotiable. Many of these systems reside in air-gapped environments or require strict SOC2 and HIPAA compliance. A critical infrastructure modernization visual project must prioritize data sovereignty.

Replay is built for these high-stakes environments. It offers On-Premise deployment options, ensuring that sensitive screen recordings of energy grids or medical records never leave the secure perimeter. This is a critical distinction from generic AI code assistants that require sending data to public LLMs.

The Role of "Flows" in Architecture#

Beyond individual components, the architecture of a SCADA system depends on complex state machines. Replay’s Flows feature maps the user journey from screen to screen. This allows architects to visualize the entire application's state tree before writing a single line of backend integration code.

typescript
// Replay Blueprint: Navigation Flow for Alarm Escalation
export const AlarmEscalationFlow = {
  id: "flow_alarm_001",
  startNode: "Dashboard_Main",
  steps: [
    {
      action: "ALARM_TRIGGER",
      source: "Dashboard_Main",
      destination: "Alarm_Detail_View",
      logic: "Requires Level 2 Authorization"
    },
    {
      action: "ACKNOWLEDGE_ALARM",
      source: "Alarm_Detail_View",
      destination: "Resolution_Form",
      capturedFields: ["operator_id", "timestamp", "resolution_code"]
    }
  ]
};

By defining these flows visually, the development team can ensure that the new React application maintains 100% functional parity with the legacy system, a requirement for Modernizing Regulated Systems.

Accelerating the Timeline: From Years to Weeks#

The most significant advantage of using Replay for critical infrastructure modernization visual projects is the compression of the "Discovery" phase. In a traditional project, discovery takes 25% of the total timeline. With Replay, discovery happens in real-time as you record the legacy system.

Consider a large-scale utility provider with 500 unique HMI screens.

• •Manual approach: 20,000 hours (roughly 10 developers working for a year).
• •Replay approach: 2,000 hours (roughly 2 developers working for 6 months, or 4 for 3 months).

This 70% average time saving allows organizations to reallocate their budget toward high-value features like predictive maintenance AI or advanced data visualization, rather than just "catching up" to the current UI standards. For more on how to structure these projects, see our guide on Enterprise Design Systems.

Overcoming the "Documentation Gap"#

As mentioned, 67% of legacy systems lack documentation. This is the "silent killer" of modernization projects. When the code is undocumented, the UI is the only remaining map of the business logic.

By using Visual Reverse Engineering, the UI becomes the specification. Replay’s Blueprints serve as a living document that bridges the gap between the old-world COBOL or Delphi logic and the new-world React/Next.js architecture. This ensures that even if the original developers are long gone, their institutional knowledge is preserved in the modern code base.

According to Replay’s analysis, projects that use visual extraction are 4x more likely to be completed on time compared to those relying on manual code analysis. This is because visual cues are unambiguous; a button either triggers a modal or it doesn't. Code, however, can be full of dead paths and "zombie logic" that hasn't been used in a decade but still confuses manual reviewers.

The Future of Industrial UI#

The shift toward critical infrastructure modernization visual techniques is part of a broader trend in "Visual-First" development. As generative AI continues to evolve, the ability to provide high-fidelity visual context—like a video of a working system—will be the differentiator between generic code generation and precise, mission-critical engineering.

For industries like Telecom, Manufacturing, and Government, the goal isn't just to look modern; it’s to be maintainable. A React component library generated by Replay is modular, testable, and documented. It turns a liability (technical debt) into an asset (a modern Design System).

Frequently Asked Questions#

How does visual reverse engineering handle complex data visualizations in SCADA?#

Visual reverse engineering with Replay captures the behavior and styling of complex elements like trend charts, heat maps, and gauges. It identifies the data inputs required for these components, allowing developers to swap the legacy data source with a modern API while keeping the visual representation consistent.

Is Replay secure enough for government or utility infrastructure?#

Yes. Replay is built for regulated environments and is SOC2 and HIPAA-ready. For critical infrastructure, we offer On-Premise installations where all video processing and code generation happen within your own secure network, ensuring no data ever touches the public cloud.

Can Replay extract logic from thick-client applications like Delphi or VB6?#

Absolutely. Because Replay uses visual recording and AI-driven pattern recognition, it is agnostic to the underlying source code. Whether the legacy system is a 30-year-old Windows XP application or a Java Applet, if it can be displayed on a screen, Replay can convert it into modern React components.

How does this approach save 70% of the time?#

The majority of a rewrite's time is spent on "Discovery" and "UI Reconstruction." Replay automates both. Instead of a developer manually inspecting a screen and writing CSS/HTML to match it, Replay's video-to-code engine generates the code in seconds. This moves the developer's role from "builder" to "editor," which is significantly faster.

What happens to the back-end integration?#

Replay focuses on the frontend and the "Flow" of the application. It provides a clear blueprint of what data is needed where. This allows your backend team to build targeted APIs or middleware (like GraphQL or tRPC) to feed the new React frontend, rather than trying to reverse-engineer the entire backend database schema at once.

Ready to modernize without rewriting? Book a pilot with Replay