portfolio β€” Jonathan Frecker
_hello.razor Γ—
_about.md Γ—
cs _projects.cs Γ—
_skills.json Γ—
cs _principles.cs Γ—
_experience.md Γ—
_contact.razor Γ—
Jonathan Frecker

const developer = "Jonathan Frecker";

Jonathan Frecker

//

I've spent ten years making systems talk to each other β€” from financial platforms and in-house C# applications to HL7 feeds, DICOM workflows, and clinical APIs. Now I'm applying that foundation as I transition into a full-time software engineering role.

01. About Me

// _about.md β€” who I am and how I got here

I've been working in technology for over ten years across two industries. I started on the ground floor of a stockbroking firm β€” Messenger, then IT Support, then Junior Programmer β€” writing C# applications, managing SQL servers, building SSRS reports, and eventually working independently as the sole programmer after our senior developer left. That environment taught me how to ship under pressure with real business consequences.

From there I moved into healthcare IT, spending the last five years delivering and supporting HL7 and DICOM integrations across RIS and PACS environments. I now work at the intersection of clinical operations and technical systems β€” where data reliability isn't optional and multi-vendor troubleshooting is a daily discipline.

My current focus is moving fully into software engineering and systems architecture β€” building with C# and .NET, running a self-hosted homelab on Proxmox, and working toward cloud-native deployments on Azure. A few things I work with regularly:

C# / .NET SQL / SSRS / SSIS HL7 / DICOM / FHIR Docker Linux / Proxmox REST APIs
10+
Years in Technology
100s
Interoperability Integrations
5+
Years in Healthcare Integration
Zero-Trust
Security Principle

02. Projects

// _projects.cs β€” things I've built

🟒 Delivered

Fee Disclosure Statement System

A production C# WinForms application built and owned end-to-end at E. L & C Baillieu β€” automating ETL, SQL-driven SSRS reporting, and email delivery to ~2,000 clients. First time owning a business-critical system solo, under real production pressure, after the senior developer departed.

C# WinForms SQL Server SSRS SSIS
🟒 Live

TheGrid β€” Homelab Platform

A self-hosted Proxmox cluster built and operated as a personal cloud platform β€” real infrastructure, real constraints, and zero exposed ports to the public internet.

Proxmox Docker Caddy Tailscale Cloudflare
🟒 Live

Self-Hosted AI Stack

A self-hosted AI environment pairing a chat/dev-assistant frontend with a locally-run open-weight LLM inference server on dedicated GPU hardware.

Docker NVIDIA Jetson llama.cpp Caddy OpenWebUI
🟒 Live

Hermes AI Agent β€” "Bit"

A self-hosted, tool-using AI agent that runs scheduled automation and answers questions over Telegram, powered by the homelab's own inference server.

Docker Telegram API Proxmox Caddy
🟒 V1 Live

Rack Temperature Monitor

Custom ESP32 firmware, written entirely in C# on .NET nanoFramework, that monitors homelab rack temperature and pushes real-time alerts.

C# .NET nanoFramework ESP32 IoT
🟒 Site Live 🟑 Back-Office In Progress

Client Hosting β€” Floor Sanding Solutions

End-to-end web presence and back-office hosting for a small business client β€” a live marketing site with a working quote pipeline, plus an isolated, zero-trust invoicing deployment.

Cloudflare Pages Cloudflare Tunnel Docker GitHub Actions
🟑 Designed

AI Security Camera System

A fully self-hosted, AI-accelerated NVR designed to replace a consumer cloud camera app β€” GPU-accelerated detection with no cloud subscription or data handling.

NVIDIA Jetson Frigate MQTT Home Assistant
🟑 WIP

HL7 Message Parser β€” .NET

A C# library for parsing and validating HL7 v2.x messages, built to deepen .NET skills in a domain I know deeply. Handles ORM, ORU, and ADT message types, extracting structured segment data into typed objects for downstream processing.

C# .NET 8 xUnit HL7 v2.x
🟑 WIP

Integration Monitor Dashboard

A lightweight web dashboard for monitoring HL7 interface engine activity β€” parsing message counts and error rates by interface from log exports and surfacing them in a browser UI, built to replace manually combing through log files.

JavaScript SQL HL7 REST API
🟒 Live

InvoiceMate

A C# desktop app that manages customers, generates invoices, and automates financial reporting for a small business β€” one of my first production systems, built in 2018 and still running today.

C# WinForms SQL Server SSRS
🟒 Live

Self-Hosted Docs MCP Server

A read-only Model Context Protocol server built in .NET that connects Claude to a self-hosted documentation knowledge base β€” giving an AI assistant real tool-use to search, browse, and read pages, not just chat.

C# .NET MCP Claude/AI Integration

03. Skills & Tech

// _skills.json β€” { "what": "I work with" }

const languages = [
C# SQL JavaScript HTML / CSS Bash XML Java .NET / ASP.NET WPF / WinForms .NET nanoFramework / Embedded Systems
const integration = [
HL7 v2.x DICOM FHIR R4 REST APIs ETL / Data Migration SQL Server SSRS SSIS Power BI
const infrastructure = [
Docker Proxmox Linux (Ubuntu) Tailscale Cloudflare Caddy Azure (learning) Cloud Infrastructure Git
const tools = [
Active Directory Office 365 Admin Zendesk Visual Studio VS Code xUnit IRESS GBST Front Office AI Prompt Engineering

04. How I Build Software

// how I think about engineering

>_ Boring technology first

I default to proven tools over whatever is new. Complexity has a carrying cost β€” in maintenance, onboarding, and failure modes. I reach for something newer only when the trade-off is explicit and worth making.

// Understand the problem before writing code

Most bugs are specification bugs. I spend time on the "why" before the "how" β€” reading the ticket, tracing the data, asking one more clarifying question. Code written against a clear problem statement is shorter and easier to delete.

β†’ Observability is a feature

Systems that can't explain their own behaviour are expensive to maintain. I treat logging, structured errors, and clear audit trails as first-class requirements β€” not afterthoughts. If something breaks at 2 AM, the logs should tell the story.

>_ Small, working increments over big launches

Long-lived branches accumulate risk. I prefer to merge small, demonstrably correct changes often. Each increment should leave the system in a better state than it found it β€” even if the full feature isn't there yet.

// Data integrity is non-negotiable

Ten years of working in finance and healthcare has made this instinctive. Silent data corruption is worse than a visible error. I validate at boundaries, fail loudly on unexpected input, and never assume the data upstream is clean.

β†’ Write for the next engineer

Code is read far more than it is written. Names should say what a thing is, not how it works. Comments earn their place by explaining intent, not restating syntax. I write as though the person inheriting the code is smart, busy, and has no context.

05. Experience

// _experience.md β€” where I've been

Sep 2022 β€” Present
Integration Specialist β†’ Junior Developer (In Transition)
@ Kailo Medical
Design and deliver complex HL7 and DICOM integrations for Kailo Medical's KailoHub interoperability engine β€” the platform that powers clinical data exchange across the company's entire product suite. Delivered critical integrations for large medical imaging providers, practices, and hospitals across Australia, covering RIS/PACS connections, ADT workflows, order management, and result delivery. Expanded into FHIR R4 implementations as the platform evolved toward modern interoperability standards. As of September 2026, the role has grown into a dual Integration Specialist / Junior Developer capacity, under an employer-backed six-month transition plan toward a full-time developer position β€” applying the same systems knowledge to building software rather than only integrating it.
HL7 v2.x DICOM FHIR R4 REST APIs SQL KailoHub RIS / PACS Data Migration C# / .NET
  • Delivered integrations for major Australian healthcare providers across radiology, pathology, and hospital networks
  • Expanding into FHIR R4 β€” bridging legacy HL7 v2 and modern interoperability standards
  • End-to-end ownership across every integration β€” scoping, configuration, UAT, go-live, production support
  • Entered an employer-backed six-month transition plan (Sep 2026) into a full-time Junior Developer role, working a dual Integration Specialist / Developer capacity in the meantime
Jan 2021 β€” Sep 2022
Software Support Specialist
@ Kailo Medical
Joined Kailo Medical in a software support role, providing technical support for the KailoHub platform and its clinical site integrations. Rapidly developed deep expertise in HL7 messaging patterns, DICOM workflows, and the operational realities of clinical environments. As integration volume and complexity grew, the role evolved into full integration responsibilities β€” leading directly to promotion to Integration Specialist within 20 months.
HL7 DICOM SQL KailoHub Zendesk Technical Support
  • Promoted to Integration Specialist within 20 months based on technical delivery and platform expertise
  • Developed hands-on knowledge across KailoHub's full integration engine β€” configuration, message routing, error handling
  • Bridged clinical operations and technical support, translating HL7/DICOM issues for non-technical stakeholders
Jul 2018 β€” Jan 2021
IT Support & Junior Programmer
@ Baillieu Limited
Dual role combining Level 1/2 IT support with active software development at a financial services firm. Built and independently delivered a C# WinForms application for automating Fee Disclosure Statement generation β€” covering ETL of external financial data, SQL-driven SSRS report generation, and automated email delivery to approximately 2,000 clients. Sole programmer on the project after the senior developer departed. Maintained SQL Server databases, stored procedures, and the firm's broader reporting infrastructure throughout.
C# WinForms SQL Server SSRS SSIS ETL Power BI .NET Framework Active Directory Office 365
  • Sole programmer on a business-critical FDS system after senior developer departed β€” delivered on schedule under production pressure
  • Built C# WinForms application serving ~2,000 clients, handling ETL, SSRS report generation, and automated distribution end-to-end
  • Maintained production SQL Server infrastructure and reporting pipeline for a regulated financial services environment
Mar 2016 β€” Jul 2018
IT Help Desk Support Officer
@ E. L & C Baillieu
Level 1/2 Help Desk in a financial services environment supporting approximately 200 seats. Managed Zendesk ticket queues, deployed SOE builds, administered Active Directory and Office 365, and troubleshot specialist financial platforms including GBST Front Office and IRESS. Began assisting the senior developer with SQL queries and reporting work β€” a door that opened the path into programming.
Active Directory Office 365 Windows Server Zendesk GBST Front Office IRESS Networking Hardware
  • Level 1/2 support across the full firm β€” hardware, software, financial platforms, and network issues
  • First exposure to SQL and reporting work alongside the senior BA developer β€” the seed of a programming career
  • Handled Level 3 vendor escalations for specialist financial platforms
Jun 2015 β€” Mar 2016
Messenger & Data Entry Clerk
@ Baillieu Holst
Entry-level role at a stockbroking firm handling general administration, consumable inventory, cataloguing and archiving inter-business communications, and delivering contract notes. First professional exposure to a financial services environment β€” and the start of a six-year tenure that progressed through successive rebrands and three promotions, from the ground floor to programmer.
Administration Data Entry Inventory Management
  • Foundation of a six-year tenure: Baillieu Holst β†’ E. L & C Baillieu β†’ Baillieu Limited
  • Progressed Messenger β†’ IT Support β†’ Programmer across three successive roles

06. Get in Touch

// _contact.razor β€” let's build something

I'm currently mid-transition into a full-time developer role at Kailo Medical, so I'm not actively job hunting right now. That said, I'm always keen to talk shop, swap ideas, or hear about interesting work β€” in healthcare tech, cloud infrastructure, systems integration, or homelab builds. If that's you, or you just want to connect for down the line, feel free to reach out.