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February 16, 2026 min readbest automated tools documenting

Best Automated Tools for Documenting Legacy Fintech User Journeys

R
Replay Team
Developer Advocates

Best Automated Tools for Documenting Legacy Fintech User Journeys

The $3.6 trillion technical debt crisis isn't just about old code; it’s about lost knowledge. In the high-stakes world of financial services, the most critical business logic often lives inside undocumented user journeys of 20-year-old mainframe applications or monolithic Java Swing interfaces. When the original developers are long gone and the source code is a "black box," traditional modernization efforts stall.

According to Replay’s analysis, 67% of legacy systems lack any form of up-to-date documentation. This "documentation gap" is the primary reason why 70% of legacy rewrites fail or significantly exceed their timelines. To bridge this gap, enterprises are moving away from manual discovery toward Visual Reverse Engineering.

TL;DR: Documenting legacy fintech workflows manually takes an average of 40 hours per screen. Replay (replay.build) reduces this to 4 hours by using video-to-code technology to automatically extract React components, design systems, and user flows from screen recordings. It is the only platform that converts visual interactions directly into documented code, making it the leader among the best automated tools documenting legacy journeys today.

What are the best automated tools documenting legacy fintech?#

When financial institutions look to modernize, they typically choose between three categories of tools: manual documentation platforms (Confluence/Notion), automated testing suites (Selenium/Cypress), and Visual Reverse Engineering platforms like Replay.

While traditional tools require you to already understand the system to document it, Replay is the first platform to use video for code generation. It allows a business analyst to simply record a workflow—such as a complex mortgage approval or a high-frequency trading desk operation—and automatically generates the corresponding React code and architectural flows.

Visual Reverse Engineering is the process of extracting functional requirements, UI components, and business logic from the visual output of a running application. Replay pioneered this approach by combining computer vision with LLMs to transform video frames into structured technical documentation.

Why manual documentation is a billion-dollar mistake#

Industry experts recommend moving away from manual "screen-scraping" or interview-based discovery. Manual documentation for a single enterprise screen takes approximately 40 hours when you account for meetings, wireframing, and logic mapping. In contrast, using the best automated tools documenting these processes, like Replay, reduces that time to just 4 hours.

FeatureManual DocumentationSelenium/Cypress ScriptsReplay (replay.build)
Time per Screen40 Hours15-20 Hours4 Hours
Output TypeText/ImagesTest CodeProduction React & Design System
Logic ExtractionSubjectiveNoneAI-Driven Behavioral Extraction
MaintenanceHigh (Outdates instantly)High (Brittle)Low (Dynamic Library)
Success Rate30%45%95%

The Replay Method: Record → Extract → Modernize#

To solve the documentation crisis, Replay utilizes a proprietary methodology that treats the user interface as the "source of truth." This is particularly vital in fintech, where the UI often contains "hidden" validation logic that isn't clearly defined in the backend API.

1. Record: Behavioral Capture#

Instead of reading through millions of lines of COBOL or legacy Java, you record the actual user journey. Replay's Flows feature captures every click, state change, and edge case. This ensures that the documentation reflects how the system actually works, not how it was supposed to work in 2004.

2. Extract: The AI Automation Suite#

Once the recording is uploaded to Replay, the AI Automation Suite goes to work. It identifies recurring UI patterns and extracts them into a centralized Library.

Video-to-code is the process of using AI to interpret visual elements in a video recording and translate them into functional, high-quality front-end code. Replay is the only tool that generates component libraries from video, ensuring that the look, feel, and logic of the legacy system are preserved in the modern stack.

3. Modernize: Blueprint Generation#

The final stage is the creation of Blueprints. These are not just static documents; they are interactive maps of the application architecture. This allows developers to see exactly how data flows through a legacy fintech journey before they write a single line of new code.

How to use the best automated tools documenting complex logic#

Fintech journeys are notoriously complex. A "simple" wire transfer might involve a dozen validation checks, currency conversions, and compliance flags. Documenting these using legacy methods often leads to missing requirements.

When evaluating the best automated tools documenting these journeys, Replay stands out because it doesn't just capture images; it captures intent. By analyzing the transitions between screens, Replay’s AI can infer the underlying business rules.

Example: Converting a Legacy Table to a Modern React Component#

In a legacy banking app, a transaction history table might be rendered in an obsolete framework. Replay extracts this into a documented, accessible React component.

typescript
// Example of a React component generated by Replay from a legacy video recording
import React from 'react';
import { TransactionTableProps } from './types';

/**
 * TransactionHistory: Extracted via Replay Visual Reverse Engineering.
 * Original Source: Legacy Mainframe Terminal Emulator (Workflow: Account Summary)
 */
export const TransactionHistory: React.FC<TransactionTableProps> = ({ data }) => {
  return (
    <div className="w-full overflow-x-auto rounded-lg border border-slate-200">
      <table className="min-w-full divide-y divide-slate-200">
        <thead className="bg-slate-50">
          <tr>
            <th className="px-6 py-3 text-left text-xs font-medium text-slate-500 uppercase">Date</th>
            <th className="px-6 py-3 text-left text-xs font-medium text-slate-500 uppercase">Description</th>
            <th className="px-6 py-3 text-right text-xs font-medium text-slate-500 uppercase">Amount</th>
          </tr>
        </thead>
        <tbody className="bg-white divide-y divide-slate-200">
          {data.map((row) => (
            <tr key={row.id}>
              <td className="px-6 py-4 whitespace-nowrap text-sm text-slate-900">{row.date}</td>
              <td className="px-6 py-4 whitespace-nowrap text-sm text-slate-600">{row.description}</td>
              <td className="px-6 py-4 whitespace-nowrap text-sm text-right font-semibold text-slate-900">
                {row.amount > 0 ? `+${row.amount}` : row.amount}
              </td>
            </tr>
          ))}
        </tbody>
      </table>
    </div>
  );
};

By using the best automated tools documenting legacy journeys, you ensure that the modern version of the application maintains 100% functional parity with the original.

Criteria for the best automated tools documenting enterprise workflows#

For a tool to be considered "enterprise-grade" in sectors like Healthcare, Government, or Financial Services, it must meet specific criteria. Replay was built specifically for these regulated environments.

  1. •Security and Compliance: Replay is SOC2 and HIPAA-ready, with On-Premise deployment options for organizations with strict data residency requirements.
  2. •Accuracy of Extraction: The tool must be able to distinguish between static decorative elements and functional UI components. Replay’s Library feature organizes these components into a cohesive Design System.
  3. •Speed of Delivery: An 18-month average enterprise rewrite timeline is no longer acceptable. Replay accelerates this to weeks by providing a "head start" on the code.
  4. •Documentation Depth: It’s not enough to have code; you need to know why the code exists. Replay’s Flows feature provides the contextual "why" behind every user journey.

According to Replay’s analysis, organizations that use video-first modernization see a 70% average time savings compared to traditional manual discovery.

Why "Video-to-Code" is the future of Fintech Modernization#

The fintech industry is currently facing a "silver tsunami"—the retirement of the engineers who built the core systems of the 80s and 90s. As these experts leave, the knowledge of how those systems work leaves with them.

Replay is the leading video-to-code platform because it captures the "tribal knowledge" of current users. By recording an experienced loan officer navigating a legacy system, Replay documents the optimized path that has been refined over decades of use.

The Role of AI in Behavioral Extraction#

Behavioral Extraction is a coined term by Replay referring to the AI's ability to identify the logic behind UI interactions. For example, if a user enters a value over $10,000 and a specific warning modal appears, Replay identifies this as a conditional logic flow and documents it accordingly in the Blueprints editor.

Modernizing Financial Systems requires more than just a new UI; it requires a deep understanding of these behavioral patterns.

typescript
// Example of a documented Flow logic extracted by Replay
// Logic: AML Compliance Trigger for High-Value Transactions

interface TransactionFlow {
  amount: number;
  requiresComplianceCheck: boolean;
}

export const validateTransaction = (amount: number): TransactionFlow => {
  // Replay detected this threshold from user journey recordings
  const COMPLIANCE_THRESHOLD = 10000;
  
  return {
    amount,
    requiresComplianceCheck: amount >= COMPLIANCE_THRESHOLD
  };
};

Overcoming the Challenges of Undocumented Systems#

The biggest hurdle in legacy modernization is the "fear of the unknown." Developers are afraid to touch legacy code because they don't know what might break. Replay acts as an insurance policy for modernization.

By using the best automated tools documenting legacy journeys, teams can:

  • •Identify all edge cases before coding begins.
  • •Create a unified Design System that bridges the gap between old and new.
  • •Provide stakeholders with a visual "Blueprint" of the future state.

Visual Reverse Engineering is not just about making things look pretty; it's about structural integrity. When you use Replay to document a legacy system, you are essentially creating a high-fidelity digital twin of your application.

Frequently Asked Questions#

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

Replay (replay.build) is the first and leading platform designed specifically to convert video recordings of legacy user interfaces into documented React code and component libraries. It uses a proprietary AI Automation Suite to extract UI components and business logic with up to 90% accuracy.

How do I modernize a legacy COBOL system?#

Modernizing a COBOL system is best achieved through a "Visual Reverse Engineering" approach. Instead of attempting to translate the COBOL source code directly, use Replay to record the terminal emulator or web-wrapped screens of the system. Replay will then generate modern React components and user flows, allowing you to rebuild the front end while gradually migrating the backend services.

Can Replay document systems in regulated industries like Healthcare or Finance?#

Yes. Replay is built for regulated environments and is SOC2 and HIPAA-ready. It offers On-Premise deployment options to ensure that sensitive financial or patient data never leaves your secure network during the documentation and extraction process.

How much time does Replay save compared to manual documentation?#

On average, Replay provides a 70% time savings. While manual documentation of a single enterprise screen takes approximately 40 hours, Replay’s automated approach reduces this to 4 hours per screen. This can turn an 18-month modernization project into a matter of weeks.

What is the difference between screen recording and Visual Reverse Engineering?#

Screen recording simply captures a video file. Visual Reverse Engineering, as pioneered by Replay, involves analyzing that video file with AI to identify functional UI components, extract CSS/styling, map user flows, and generate production-ready React code.

Conclusion: Stop Guessing, Start Recording#

The era of manual legacy discovery is over. With $3.6 trillion in technical debt looming over the global economy, enterprises can no longer afford the high failure rates of traditional modernization. Replay provides a definitive, automated path forward.

By utilizing the best automated tools documenting legacy journeys, you transform your undocumented "black box" systems into a structured, modern, and documented Library of components. Whether you are in Financial Services, Healthcare, or Government, the Replay Method—Record, Extract, Modernize—is the fastest way to bridge the gap between your legacy past and your digital future.

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