JOHN DU PREEZ
Senior Full Stack Developer
Crafting robust and scalable digital experiences.
Professional Summary
Overview
A results-driven Senior Full Stack Developer with extensive experience in designing, developing, and modernizing complex web applications and services. Proven ability to reduce technical debt and streamline business processes by architecting and implementing robust, scalable solutions. Expertise in frontend technologies like React and Angular, coupled with strong backend skills in .NET, C#, and databases (ex. SQL Server, MongoDB). A collaborative team player and mentor, committed to delivering high-quality code and impactful digital experiences for high-profile clients.
Work Experience
Senior Software Developer
Dec 2023 – Present
Green Leaf Solutions
- Leading the complete overhaul of internal IT systems, designing and replacing legacy applications to streamline critical business processes.
- Architected an integrated system using React, .NET Core API, and MSSQL, connecting patient portals, a central ticketing hub (Intercom), and accounting software (Xero).
React
.NET Core
MS SQL Server
Intercom API
Xero API
Senior Full Stack Developer
Jun 2022 – Dec 2023
Valocity Global
- Developed and enhanced features for the Nexus platform, a real estate data hub, using Angular for the frontend to improve system functionality and user experience.
- Mentored junior developers and performed regular code reviews to ensure code quality.
Angular
Senior Full Stack Developer
Dec 2018 – May 2022
TRACK NZ
- Delivered web frontend solutions in React for major clients including McDonalds, Westpac, and Mobil.
- Led the development of high-engagement web campaigns for McDonalds, such as "Battle of the Burgers" and "El Maco," driving user interaction and delivering in-app offers.
React
REST APIs
SQL
Node.js
Salesforce
Marketo
MongoDB
Senior Software Developer
Mar 2015 – Dec 2018
Go Car Finance
- Architected and built the company's primary loan application system from the ground up using React.
- Developed and launched cross-platform mobile apps for customers and installers using React Native.
React
React Native
Windows Services
SQL Server
NZTA API
SurveyMonkey API
Senior Software Developer
Jul 2014 – Feb 2015
Market Pulse International
- Developed the "Smartfeedback" survey platform using React, which displayed customer survey responses with interactive graphs and trend analysis.
- Maintained a core CRM survey service that automated the distribution and processing of surveys.
React
Windows Services
SQL
Web Services (Email/SMS)
FTP
Senior Web Developer
2013 – Jun 2014
Blackhawk Tracking Systems
- Designed and developed a sales application dynamically generated from a SQL database, allowing for rapid structural changes without redeployment.
- Created a visual workflow engine using GoJS and implemented a geofencing feature using the Google Maps API for location-based alerts.
ASP.NET MVC
SQL Server
GoJS
Google Maps API
Senior Analyst Programmer
2012 – Jan 2013
Real People
- Developed and maintained Windows services and a ClickOnce frontend used by over 200 call centre agents for the telesales department.
- Rewrote a legacy Windows service into a SQL Server SSIS package to process and manage QC files and recordings.
C#
WCF
Entity Framework
LINQ
ClickOnce
MySQL
Analyst Programmer
2006 – 2011
Real People
- Maintained and enhanced a property management website using ASP.NET and later converted it into a C# WinForms desktop application.
- Developed SQL jobs, stored procedures, and DTS packages to manage daily financial transactions and reporting.
ASP.NET
C# WinForms
Web Services
SQL Server
AJAX
JavaScript
Skills
Technical Skills
Frontend
React
Angular
React Native
JavaScript
HTML/CSS
AJAX
Tailwind CSS
Backend
.NET
.NET Core
C#
Node.js
REST APIs
Web Services
Windows Services
Databases
SQL Server
MongoDB
MySQL
SQL
Entity Framework
LINQ
APIs & Integrations
Intercom API
Xero API
NZTA API
SurveyMonkey API
Salesforce
Marketo
Google Maps API
Tools & Platforms
Git
Docker
GoJS
ClickOnce
SSIS
DTS packages
FTP
Soft Skills
- Results-Driven
- Problem-Solving
- Team Collaboration
- Mentorship
- Adaptability
- Effective Communication
Portfolio Highlights
Battle of the burgers - McDonalds
An engagement mechanic where customers can vote for their favourite burger. Once they voted, they would get an offer dropped in their McDonalds wallet.
Gamification
React
Customer Engagement
Food To Go - Mobil
A page that displays the current food and drinks located at different Mobil service stations. It uses the user's GPS location to get the closest station and filter the products available at that station.
Geolocation
React
Product Filtering
Premium Gamification - Mobil
A fun mechanic where customers would complete a journey by answering a couple of questions.
Gamification
Interactive Journey
React
Deal Mail - McDonalds
This page displays custom food offers for customers. A customer can select what offer they would like and once selected, it will push the offer into the McDonalds wallet.
Custom Offers
API Integration
React
El Maco - McDonalds
An engagement mechanic where customers had the chance to shake a rumba shaker (on a web page) to get into the shaking vibe. Once they have shaken a couple of times, they would get an offer dropped into their McDonalds wallet.
Gamification
Animation
React
NZDM Awards 2019: TRACK NZ and McDonald's take out Nexus Supreme and Grand Prix Prizes
TRACK NZ and McDonald's have emerged as the big winners of the night, picking up both the Nexus Supreme and Grand Prix Prize for their transformational, customer-centric campaigns.
Award-Winning
Campaign
Mobile App
Education
National Diploma, Information Technology
Nelson Mandela Metropolitan University
Get In Touch
Let's Connect
I'm always open to discussing new projects, creative ideas, or opportunities to be part of your vision.