Reverse-engineering a warehouse system without source code access

The Problem

An Isle of Wight-based online retailer specialising in jewellery-making materials had a unique challenge: they needed to rebuild their warehouse management system but had no access to the original source code.

The Situation

• Broken relationship: The relationship with the original VB6 developer had broken down
• Working but frozen: The existing system worked but couldn't be modified or extended
• No documentation: No source code, no specs, just a running application

The Task

Essentially a "stealth re-implementation" - reverse-engineer the functionality by observing the existing system's behaviour and rebuild it in modern technologies.

Our Approach

We treated the existing application as a black box specification.

Reverse Engineering

• Behaviour observation: Documenting what the system did by using it
• Data structure inference: Understanding the underlying model from Access database inspection
• Workflow mapping: Tracing business processes through the existing interface

Modern Rebuild

Built the new system as a WPF desktop application:

• C#/.NET: Modern, maintainable codebase
• MongoDB: Replacing Microsoft Access for the data layer
• Performance improvements: Modern architecture delivering significant speed gains

Predictive Analytics

Added capability the original system lacked:

• Stock level monitoring: Continuous evaluation against sales trends
• Replenishment prediction: Forecasting when stock would need reordering
• Proactive planning: Turning reactive inventory management into forward-looking operations

Outcomes

Technical Delivery

• Warehouse management system rebuilt from observed behaviour
• Access to MongoDB migration with performance improvements
• Predictive stock analytics added beyond original functionality

Architecture Upgrade

• Modern C#/WPF replacing VB6
• MongoDB enabling features not possible with Access
• Foundation for future enhancements

Fractional Delivery

Delivered as sole technical resource while running concurrent engagement, demonstrating ability to manage multiple client relationships.

Honest Outcome

The project was significantly developed but never reached production. COVID-19 disrupted the timeline - the client put the project on hold during the pandemic and didn't resume afterward. The technical work was complete; external circumstances prevented deployment.

This experience demonstrates that successful technical delivery doesn't always mean production deployment - sometimes business circumstances intervene despite solid engineering work.