Introduction

KARL JAN S. REGINALDO

As a software engineer, I specialize in building full-stack applications. I leverage Flutter to craft high-performance, cross-platform mobile apps, and use Next.js and Nuxt.js to build robust, server-rendered web applications. backend, I use Nest.js to develop modular and testable applications.
Developer
If you don't fail, you're not even trying
– Denzel Washington

Tech Stacks

This section showcases the technical stacks I've mastered throughout my 4 years as a software engineer in the Philippines. I am committed to continuous learning and adapting to emerging technologies to deliver modern and efficient solutions.

Testimonials

Here are testimonials from previous colleagues, clients, and respected industry experts I've had the pleasure of working with.
Karl and I connected in 2021 over our shared passion for Flutter. He was always eager to learn more about mobile development, and I knew that with his dedication, he would soon land a great role as a Flutter developer.– Jan Salvador Sebastian | Mobile Engineer
Karl was my co-worker at a previous company. He's a mobile app guru and a competent tester, often finding subtle but important bugs in my applications.– Edward Jason Marin | Full Stack Engineer
Karl is young for this industry, but he consistently exceeded my expectations. He is adaptable to any assignment, and I was delighted to have him on my project.– Mark Padilla | Businessman
As a freelance UI/UX designer, Karl has been an invaluable resource for me. He helped me to generate new ideas and explore different design options with my clients.– Kathlyn Jordan | UI/UX Designer
Karl and I are cousins-in-law. He's always been curious about technology; whenever he'd visit, he would watch me work and ask insightful questions about what I was building.– Erwin Atuli | Sr. Backend Developer
He guided me in learning Flutter and Nest.js for backend development, and he later helped me find freelance work. He's been a great mentor. As his brother, I've seen his dedication and positive traits firsthand.– Kyle Reginaldo | Full Stack Developer
Sir Karl helped me create web and mobile applications. He shared best practices with me that are invaluable for my career. His diligence and high standards for project delivery show he has the qualities of a great project manager.– Jannray Mostajo | Mobile App Developer
In terms of his thinking, Sir Karl is quite imaginative. He explains his concepts using real-world examples, which makes it much easier for me to visualize and create the designs.– Kimberly Bay | Graphic Designer

Experience

This timeline highlights my professional journey over the last 4 years. Starting my career at 20, I've had a productive and enriching experience, learning immensely from my past roles and colleagues.
XUBE PTY LTD
As part of the team, I am developing a mobile application to visualize rich data from IoT devices. My responsibilities also extend to the backend, where I contribute to infrastructure development and the creation of REST APIs.
Full-time · July 2023 - 2025
Zurich, Switzerland
Mobile App
Backend: AWS CDK
Hardware: IoT
Bharosa PH
Working as a part-time Flutter developer on an app for scheduling medical services.
Part-time · June - Dec 2023
Davao City, Philippines
Mobile App
Android and iOS
StorageX Corporation
Developed both the consumer-facing mobile application and an administrative web dashboard using Flutter and Next.js.
Full-time · 2+ years exp
Greenhills San Juan, Philippines
Mobile App (including Internal)
Dashboard (Web)
Landing Page (Web)
Software Engineer
Sep 2021 - May 2023
Flutter Developer
Jun 2021 - May 2023
Avyan Global | Avyan Holdings
As a Mobile Developer, I developed a mobile app using Flutter for one of their clients.
Part-time · 3 months exp
Pasig City, Philippines
Mobile App
Actively contributed to multiple open-source Flutter packages by submitting pull requests, raising and resolving issues, and enhancing features. Collaborations included projects related to BLE, UI components, deployment tools, and API integrations. This involvement not only improved community packages but also deepened my understanding of scalable and reusable Flutter architecture.
2023 - Present
Plugins
Packages
Developed a home service booking application from the ground up. The app connects customers with trusted service providers for cleaning, repairs, and more.
1 1/2 years
Figma
Flutter
Supabase
Android and iOS
Crypto App
Developed a blockchain-based mobile application for a client of Avyan Global. This project involved integrating with blockchain technologies and deepened my understanding of decentralized applications.
1 & 1/2 months
Blockchain
Figma
NodeJS
Biometrics
Flutter
Asana
Android and iOS
Independently developed and published a VS Code extension to streamline the process of running React applications, born out of a desire to improve my personal development workflow.
1 day
Vscode Extension
Typescript
React Run
My first freelance project before starting my first full-time role. I developed a mobile app to showcase condominium properties, featuring different apartment layouts and details.
2 months exp
Work with Rest APIs
Android Only
Flutter
Coffee Loyalty App
Built a digital loyalty application for a coffee shop, allowing customers to collect virtual stamps and redeem rewards, replacing a traditional paper-based system.
1 month exp
QR Code
Figma
Flutter
Firebase
Android and iOS
Safeguard Security Group
Developed an application for a security agency to help track guard locations and responsibilities within a building, improving operational awareness.
1 month exp
QR Code
Flutter
Firebase
Android and iOS
IOT Monitor App
Created a native Android application to monitor and display real-time data from an IoT device (Arduino), using Firebase as the backend to receive data uploads.
1 month exp
Android Studio
Firebase
Android Only
Cleaning Management App
Developed a mobile tool for janitorial staff at schools to assign and track cleaning responsibilities, featuring time tracking with photo verification.
1 week exp
Firebase
Figma
Flutter
Android Only
Cleaning Management Web App
Built a companion web application for managing janitorial staff, providing a dashboard to view performance statistics and schedule cleaning tasks.
2 months exp
Web
NuxtJs
Firebase
Attendance Management App
Developed a student-facing mobile app for a school, allowing students to view their attendance records and monitor absences.
1 month exp
Mobile App
Flutter
Android Only
Laundry Booking App
Created a laundry booking application that allows users to schedule services and track the status of their orders from pickup to delivery.
2 months exp
Firebase
Figma
Android and iOS
Flutter
Disaster Hazard Map App
Developed a disaster awareness application that displays a color-coded hazard map, helping residents identify potential risks in their vicinity using Mapbox.
1 week exp
Firebase
Figma
Mapbox
Flutter

Showcase

These are all the projects I've worked on since 2021.
  • Github
  • Postman
  • Figma
  • VSCode
  • Github
  • Postman
  • Figma
  • VSCode
  • Github
  • Postman
  • Figma
  • VSCode
My Portfolio