SupTech Apps

My role as an App Developer

Overview

During my time at SupTech, I took on the challenge of building two large-scale mobile applications in Flutter—the SupTech Consumer App (C-end) and SupTech Technician App (T-end). I was not only responsible for designing and coding these apps but also took on roles typically divided among multiple teams in larger companies.

Throughout the process, I specialized in:

  1. Full-cycle App Development: from requirement gathering, system architecture, responsive UI design, to final deployment on both iOS and Android.
  2. Cross-platform Flutter: building robust, fluid interfaces supporting multiple languages (English, Simplified Chinese, Traditional Chinese).
  3. Backend Integration: initially leveraging Firebase-based serverless functions (Node.js) for rapid prototyping, then moving to a MySQL/Java architecture to ensure stable data synchronization, authentication, push notifications, and real-time location tracking.
  4. Stripe Payment Integration: implementing secure payment flows, creating and attaching payment methods, and enabling technicians to bind their bank accounts for receiving payouts.
  5. Team Coordination & Leadership: bridging communication between stakeholders, gathering app requirements, leading daily stand-ups, and guiding new hires. I also assumed responsibilities like a Project Manager, documenting tasks, drawing mind maps, making swimlane diagrams, and clarifying business logic with the in-house or external tech teams.

Below is a more detailed breakdown of my work.


Downloads

SupTech Consumer App

Download on iOS
Download on Google Play

SupTech Technician App

Download on iOS
Download on Google Play

Download the Consumer App (left) or Technician App (right) for iOS & Android.


Project Highlights

From left to right: (1) The Consumer App (C-end), allowing customers to create and track repair orders; (2) The Technician App (T-end), enabling technicians to pick up tasks and communicate in real time.

1. The SupTech Consumer App (C-end)

Purpose: Provide consumers with an easy way to request installation/repair services, track order statuses, chat with assigned technicians, and leverage AI Repair for self-diagnosis.

  • Built with Flutter: Ensuring a consistent UI/UX across iOS and Android.
  • User-Centric Flows:
    • Account creation & login
    • Order creation & management (brand/SKU selection, photo upload, location pin)
    • Secure online payment (integrating with Stripe)
    • Chat system (real-time messaging & photo exchange)
    • Rating and feedback
  • Internationalization (i18n): English, Simplified Chinese, Traditional Chinese.

2. The SupTech Technician App (T-end)

Purpose: Empower field technicians to view and accept nearby orders, manage scheduling, provide real-time service updates, and handle payments.

  • Location-Based Task Allocation:
    • Built real-time location services with geofencing logic (50mi radius) for relevant orders.
  • In-app Communication:
    • Integrated chat with consumers
    • Provided custom action buttons (e.g., “Depart Now,” “Begin Service,” “Complete Service”).
  • Stripe Connect:
    • Technicians can link their bank account for direct payouts.
  • Work Dashboard & Performance:
    • Real-time income stats, upcoming tasks, and completed tasks counter.

3. AI Repair Integration

I implemented a custom AI chatbot (powered by Chat GPT 4.0) within both apps—C-end and T-end—for fault diagnosis:

  • Prompt engineering: to ensure the AI’s language is user-friendly and robust enough to guide users (even novices) through potential troubleshooting steps.
  • Conversation flow: multiple-step guidance from hypothesizing the fault cause to deciding whether to do self-repair or request a technician’s visit.

4. Cross-Platform + Real-time Features

  • Hybrid Backend:
    • Legacy Firebase-based serverless functions (Node.js)
    • New MySQL/Java-based API for production scale.
  • Real-time Bidding: Technicians see instantly updated order info as location or status changes.
  • Push Notifications: Firebase Cloud Messaging for timely updates (e.g., new tasks assigned, new messages).
  • Payment Workflow:
    • Customer -> Stripe -> SupTech -> Technician
    • Delayed payout scheduling and partial refunds via custom logic.


My Additional Responsibilities

Besides solely focusing on app coding, I played multiple roles:

  • Project Manager:
    • Held requirement-gathering meetings, created mind maps and swimlane diagrams, documented all changes, and aligned them with the dev tasks.
    • Handled stakeholder requests, bridging business logic with technical feasibility.
  • Ad Hoc Tasks:
    • Assisted with HR tasks: from screening candidates to orienting new hires.
    • Built the company’s basic web presence and fixed design issues on official website.
    • Occasionally performed office errands (e.g., shipping packages, setting up coworker computers, supporting system admin tasks).
    • Engaged in cross-team communication, from clarifying B-end system queries to instructing business partners on how to utilize the new AI chat modules.
  • Release & Store Management:
    • Single-handedly managed app submissions to Apple’s App Store and Google Play.
    • Coordinated store listing, test flight/beta testing cycles, and official rollout.


Technical Contributions

Flutter Architecture

  • Implemented Provider & Riverpod for state management in different modules.
  • Optimized performance with asynchronous data streams (StreamBuilders) + caching (SharedPreferences).

Multi-Language & Internationalization

  • Organized translations in .arb/.json files, ensuring easy expansions to new languages.
  • Dynamically switched UI texts based on system language or user preference.

Stripe Payment & Connect

  • Built robust flow for PaymentMethod creation, ephemeral keys handling, PaymentIntents, and Connect-based payouts to technicians.
  • RSA encryption for sensitive data, ephemeral token usage for web hooks.

Location & Map Integrations

  • Deployed Google Maps SDK for in-app location display, technician route mapping, and geo-based filtering of tasks.
  • Handling iOS & Android location permission differences, background location updates, and UI refresh cycles.

AI Chat & Prompt Engineering

  • Built Chat GPT 4.0 conversation flows, ensuring clear step-by-step troubleshooting guides, brand/SKU/fault code recognition, and user-linguistic style adaptation.


Project Outcomes

  • Faster Customer-Provider Matching: By building a robust cross-platform solution with real-time location-based order dispatch, the company drastically reduced manual dispatch overhead.
  • Reduced Support Overhead: The integrated chat system & AI assistance lowered the number of repeated phone calls and manual troubleshooting queries.
  • Scalable Infrastructure: Transition from Firebase-based quick prototypes to a more scalable MySQL/Java environment. Performance under high concurrency improved significantly.
  • Business Value: Enhanced brand image with modern, user-friendly apps. Gained potential to expand the service across wider regions and device platforms.


Personal Growth & Reflection

Technical Mastery:

  • Deepened my expertise in Flutter, including advanced state management, custom animations, and platform-specific integrations.
  • Gained hands-on experience with Node.js serverless functions and MySQL-based microservices.

Project Management & Communication:

  • Learned to swiftly re-assess scope when business logic changed.
  • Strengthened stakeholder communication, from clarifying ambiguous requirements to training end-users.

Adaptability & Tenacity:

  • Faced tight deadlines and frequently shifting requirements.
  • Wore multiple hats—developer, coordinator, occasional HR or admin tasks—demonstrating resilience and a can-do attitude.


Final Thoughts

My experience at SupTech was both demanding and rewarding. I took pride in shipping two fully functional Flutter apps—from scratch to production—and integrating them with dynamic, AI-powered features. Though the path was challenging, I honed my full-stack understanding, sharpened my project management skills, and grew more confident as an App Developer ready for new frontiers.

I believe these experiences and the robust code I wrote can significantly contribute to any team seeking a passionate developer with multi-faceted problem-solving skills and an eye for quality software that truly serves its end users.


Additional Resources