End-to-End Digital Transformation in HealthTech

At a Glance

• Role: Full-Stack Software Engineer (Sole Developer)
• Client: CHR de la Citadelle (Major Hospital)
• Industry: HealthTech
• Timeline: 2002 – 2004
• Core Challenge: Replace an outdated, single-user Filemaker system with a robust, enterprise-grade application for managing complex cardiology patient data.
• Key Technologies: Java/J2EE (EJB 1.1, JSF), Oracle, PL/SQL, Borland Application Server

The Challenge: From Filemaker to Enterprise Java

In 2002, the hospital's cardiology department was managing critical patient data—including pacemaker implantations and cardiac catheterism procedures—on a legacy Filemaker record. This system was not scalable, secure, or suitable for a multi-user clinical environment.

The challenge was to perform a complete digital transformation. I was hired as the sole developer responsible for the end-to-end analysis, re-engineering, design, development, and maintenance of a new, modern application.

My Solution: A Service-Oriented Architecture for Critical Data

I designed and built a complete, two-part J2EE application from the ground up to serve the distinct needs of the medical staff.

1. cardiax (The Web Application): A secure, user-friendly web portal built with JSF. This was the "front-end" for clinicians. It provided a comprehensive interface for patient search, appointment scheduling, and managing detailed medical records, including multi-step forms for complex procedures like PTCA (angioplasty).
2. pcmk (The "Pacemaker" Backend): A robust "headless" backend built on EJB 1.1. This application served as the transactional "source of truth" for all pacemaker and patient device data. It was designed for data integrity, security, and to be consumed by other systems—including cardiax.

This integration between cardiax and pcmk was a classic, early example of a Service-Oriented Architecture (SOA). The web application (cardiax) acted as a consumer to the backend data service (pcmk), ensuring a clean separation of concerns between presentation, business logic, and data.

I was responsible for the entire project lifecycle, from sitting with cardiologists to understand their clinical needs, to architecting the full stack, writing the code (JSP, Java, and PL/SQL), and maintaining the system.

Why This 20-Year-Old Project Matters Today

The technology is two decades old, but the principles are timeless. This project was the foundation for the "CTO-level strategy, backed by code" approach I provide to my clients today.

1. Full Ownership & Autonomous Execution As the sole developer, I was a "Fractional CTO" before the term was popular. I was responsible for the entire technical vision, execution, and stakeholder management. This "buck stops here" mindset of total project ownership is a core part of my freelance ethic.

2. Mastering Complex Domains You cannot digitize cardiology without deeply understanding cardiology. This project taught me how to dive into a highly specialized domain (HealthTech), learn the "why" from experts (the doctors), and translate their complex needs into functional software. I apply this same rapid-domain-mastery to FinTech, MusicTech, and every new client industry I engage with.

3. Architecture is About Principles, Not Trends The EJB 1.1 and JSF are obsolete, but the architectural patterns are the direct ancestors of the work I do today.

• Separation of Concerns: The cardiax/pcmk split is the same principle as building a Spring Boot microservice for a Next.js front-end.
• Data Integrity: Using a transactional EJB backend is the same principle as ensuring data consistency in a modern, distributed FinTech system.

This project was my first experience building an end-to-end, service-oriented system. It's the starting point of the 20-year line that runs through my work in SOA, ESB, and modern Spring Boot microservice architectures.

This project proved that my passion was for building complete, robust systems that solve real-world problems. Today, I bring that same passion—backed by two decades of experience—to every client engagement.