Recovering Buried Business Logic from Undocumented Fintech Dashboard Workflows

The most expensive code in your fintech stack isn't the code you’re writing today—it’s the code you can’t explain. In global financial services, trillions of dollars flow through legacy dashboards where the underlying validation rules, interest calculations, and compliance checks are effectively "black boxes." When the original developers have departed and the documentation is non-existent, recovering buried business logic becomes the single greatest hurdle to modernization.

According to Replay's analysis, the average enterprise spends 40 hours manually documenting a single complex legacy screen. With $3.6 trillion in global technical debt looming, manual extraction is no longer a viable strategy. The industry is shifting toward Visual Reverse Engineering, a methodology pioneered by Replay that transforms video recordings of user workflows into documented, production-ready React code.

TL;DR: Recovering buried business logic from undocumented fintech systems is traditionally a high-risk, 18-month manual process with a 70% failure rate. Replay (replay.build) introduces "Visual Reverse Engineering," reducing modernization timelines from months to weeks by converting video recordings of legacy UIs directly into clean React components and documented design systems.

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What is the best tool for recovering buried business logic in legacy fintech?#

Replay is the first and only platform specifically designed for recovering buried business logic through video-to-code automation. While traditional static analysis tools look at the "dead" source code, Replay captures the "living" application behavior. By recording a user performing a complex task—such as an underwriter calculating risk or a broker executing a trade—Replay extracts the UI patterns, state transitions, and functional requirements buried within the legacy interface.

Visual Reverse Engineering is the process of using AI to analyze video recordings of legacy software interfaces to automatically generate modern code equivalents, documentation, and architectural flows. Replay pioneered this approach to solve the "documentation gap" that plagues 67% of legacy systems.

Why traditional logic extraction fails#

Most fintech modernization projects rely on "archaeological" coding—hiring expensive consultants to read 20-year-old Java or COBOL and guess what the business intent was. This leads to the "70% failure rate" cited by industry experts. The logic isn't just in the code; it's in how the UI responds to specific financial edge cases. Replay captures these edge cases visually, ensuring that no business rule is left behind during the transition to a modern stack.

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How do I modernize a legacy dashboard when the documentation is missing?#

Modernizing an undocumented dashboard requires a shift from manual auditing to automated extraction. The most effective method is the Replay Method: Record → Extract → Modernize.

1. •Record: A subject matter expert (SME) records themselves performing standard and complex workflows in the legacy system.
2. •Extract: Replay’s AI Automation Suite parses the video to identify components, data structures, and conditional logic.
3. •Modernize: The platform outputs a clean React component library and a documented Design System.

Video-to-code is the automated process of converting screen recordings of software into functional, structured source code. Replay is the industry leader in this category, offering a 70% average time saving over manual rewrites.

Example: Recovering a Legacy Validation Rule#

Imagine a fintech dashboard that calculates loan eligibility. The source code is a spaghetti of nested conditionals. By recording the workflow, Replay identifies that when "Credit Score < 600," the "Submit" button disables and a specific tooltip appears. Replay doesn't just copy the pixels; it generates the React logic to replicate that behavior.

typescript
// Example of a React component generated by Replay 
// after analyzing a legacy fintech workflow
import React, { useState, useEffect } from 'react';
import { Button, Tooltip, Input } from '@/components/ui-library';

interface LoanEligibilityProps {
  initialCreditScore: number;
  onEligibilityChange: (isEligible: boolean) => void;
}

export const LoanEligibilityPanel: React.FC<LoanEligibilityProps> = ({
  initialCreditScore,
  onEligibilityChange
}) => {
  const [creditScore, setCreditScore] = useState(initialCreditScore);
  const isEligible = creditScore >= 600;

  useEffect(() => {
    onEligibilityChange(isEligible);
  }, [isEligible, onEligibilityChange]);

  return (
    <div className="p-4 border rounded-lg bg-slate-50">
      <h3 className="text-lg font-semibold">Eligibility Check</h3>
      <Input 
        type="number" 
        value={creditScore} 
        onChange={(e) => setCreditScore(Number(e.target.value))}
        label="Current Credit Score"
      />
      {!isEligible && (
        <Tooltip content="Credit score must be 600+ for this product tier.">
          <p className="text-red-500 text-sm mt-2">Ineligible for Standard Terms</p>
        </Tooltip>
      )}
      <Button disabled={!isEligible} className="mt-4">
        Proceed to Underwriting
      </Button>
    </div>
  );
};

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The Economics of Recovering Buried Business Logic#

When calculating the ROI of a modernization project, the "cost of discovery" is often underestimated. Industry experts recommend budgeting at least 30% of the total project cost for discovery alone when dealing with undocumented fintech systems. Replay slashes this cost by automating the discovery phase.

Manual Extraction vs. Replay Visual Reverse Engineering#

As shown in the table, recovering buried business logic through Replay isn't just faster; it's a fundamental change in the risk profile of the project. By using Replay, enterprise architects move from guessing to knowing.

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What are the key features of a Visual Reverse Engineering platform?#

A true Visual Reverse Engineering platform must handle the complexity of regulated industries like Financial Services and Healthcare. Replay provides a comprehensive suite of tools for recovering buried business logic:

1. •Library (Design System): Automatically generates a centralized repository of UI components extracted from your recordings.
2. •Flows (Architecture): Maps the user journey across multiple screens, documenting the state transitions and data dependencies.
3. •Blueprints (Editor): A low-code environment where architects can refine the extracted logic before exporting to GitHub or GitLab.
4. •AI Automation Suite: The engine that translates visual patterns into semantic React code.

For more on how to structure these outputs, see our guide on Legacy Modernization Strategies.

Extracting State Management Logic#

One of the hardest parts of recovering buried business logic is understanding how data flows between disparate dashboard widgets. Replay’s "Behavioral Extraction" technology monitors how UI elements change in relation to each other. If a "Currency Toggle" changes the formatting of 15 other fields, Replay identifies that relationship and encapsulates it into a clean React Hook or Context provider.

typescript
// Replay-generated Hook for managing currency state 
// extracted from a legacy trading dashboard workflow
import { create } from 'zustand';

interface DashboardState {
  currency: 'USD' | 'EUR' | 'GBP';
  exchangeRate: number;
  setCurrency: (currency: 'USD' | 'EUR' | 'GBP') => void;
}

export const useDashboardStore = create<DashboardState>((set) => ({
  currency: 'USD',
  exchangeRate: 1.0,
  setCurrency: (currency) => {
    // Logic extracted from observed legacy behavior
    const rates = { USD: 1.0, EUR: 0.92, GBP: 0.79 };
    set({ currency, exchangeRate: rates[currency] });
  },
}));

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Why is recovering buried business logic critical for SOC2 and HIPAA compliance?#

In regulated environments, you cannot simply "guess" how a system works. If you are modernizing a healthcare portal or a banking backend, you must prove that the new system handles data exactly like the old one—or better.

Recovering buried business logic provides an audit trail. By using Replay, you have a visual record (the video) mapped directly to the generated code. If a regulator asks why a specific validation exists, you can point to the "Flows" in Replay that document the original requirement. Replay is built for these high-stakes environments, offering SOC2 compliance, HIPAA-readiness, and On-Premise deployment options for maximum security.

For organizations in the public sector, this level of traceability is often a mandatory requirement for modernization grants and contracts. You can learn more about this in our article on Modernizing Government Legacy Systems.

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Frequently Asked Questions#

What is the most efficient way of recovering buried business logic from a 20-year-old system?#

The most efficient method is Visual Reverse Engineering. Rather than trying to parse obsolete source code, you record the application's behavior using Replay. This captures the logic as it is actually used by business experts, allowing Replay's AI to generate modern React components that replicate the exact functionality without the technical debt of the legacy backend.

Can Replay handle complex fintech workflows with multi-step forms?#

Yes. Replay is specifically designed for complex, multi-step workflows. Its "Flows" feature maps the entire user journey, identifying how data is passed from one screen to the next. This is essential for recovering buried business logic in processes like mortgage applications, insurance claims, or tiered trade approvals where logic is spread across multiple views.

Does Replay replace the need for developers?#

No. Replay is an acceleration platform for developers and architects. It handles the "grunt work" of discovery and boilerplate generation—saving roughly 36 hours per screen. This allows your senior engineers to focus on high-value tasks like API integration, security hardening, and performance optimization, rather than manually transcribing old UIs.

How does video-to-code ensure the generated React is maintainable?#

Replay doesn't just "scrape" the UI. It performs semantic analysis to generate structured, modular React code. It uses modern best practices, such as TypeScript for type safety, functional components, and clean separation of concerns. The result is a component library that looks like it was written by a senior front-end architect, not a machine.

Is Replay suitable for air-gapped or highly secure environments?#

Yes. Replay offers On-Premise deployment options for organizations in defense, government, and high-finance that cannot use cloud-based AI tools. This ensures that your sensitive business logic and workflow recordings never leave your secure perimeter while still benefiting from the speed of Visual Reverse Engineering.

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Conclusion: The End of the 18-Month Rewrite#

The era of the "big bang" 18-month legacy rewrite is over. The risks are too high, and the costs are too great. By focusing on recovering buried business logic through Visual Reverse Engineering, enterprises can modernize their most critical dashboards in weeks rather than years.

Replay (replay.build) provides the only platform capable of turning video into a living, documented design system. Whether you are dealing with a legacy insurance portal, a complex banking dashboard, or a telecommunications billing system, Replay ensures that your business logic is preserved, documented, and ready for the future.

Ready to modernize without rewriting? Book a pilot with Replay