Calvin Harsono

Flutter Developer with 2+ years of commercial experience building production-grade, cross-platform mobile applications. Specialises in AI integrations — including LLM APIs (Gemini) and computer-vision-adjacent features — backed by clean BLoC architecture and RESTful API connections. Proven delivery of apps to Google Play Store, with hands-on experience in Python Flask backends, vector database search, and real-time data pipelines.

Conversational

English speaker comfortable in international, remote-first teams.

Mobile Developer - PT Kode Aplikasi Indonesia - Surabaya, Indonesia (WFH)

(2025-11)

• Develop and maintain Android applications using Flutter, Kotlin Multiplatform (KMP), and Native Kotlin.
• Contribute to the development of Agen 2.0 (Pegadaian) by implementing new features and maintaining application quality.
• Develop Trima+ Picks (Trimegah) using Kotlin Multiplatform (KMP) for cross-platform mobile development.
• Support API migration and application enhancement for MAXstream.
• Maintain and improve the MyMRTJ application through bug fixes, feature enhancements, and performance improvements.

Lead Mobile Developer - PT Zona AI Indonesia - Surabaya, Indonesia (WFH)

(2024-09 - 2026-05)

• Built and deployed a faceswap AI feature: designed the REST API endpoint, integrated a computer-vision model, and shipped the client as a Flutter Web application hosted on Firebase Hosting.
• Develop and built a Sports Analysis on Android App using Flutter and Gemini Vision API for analysing basketball and workout moves.
• Owned the full delivery pipeline — from API design through front-end integration to production deployment — without a dedicated DevOps resource.

Mobile App Developer - PT Izzati Hasanah - Jakarta, Indonesia (WFH)

(2024-06 - 2025-07)

• Developed a Flutter + Firebase mobile application for employee quotation management and attendance tracking, replacing a manual process for the operations team.
• Integrated RESTful APIs and managed real-time Firestore data sync; authored code documentation and conducted QA testing on the live web platform.

Lecturer Assistant - Institut Sains dan Teknologi Terpadu Surabaya - Surabaya, Indonesia

(2024-02 - 2026-05)

• Engineered an AI-powered Sport Analysis app using Flutter, Firebase, and the Gemini LLM API, integrating real-time AI inference into the mobile client.
• Built a GDG Surabaya event app in Flutter, supporting live attendee interactions during the IOX event.
• Researched LLMware for multimodal PDF extraction (text, tables, images), contributing to academic coursework on document intelligence.

Junior Laboratory Assistant - Institut Sains dan Teknologi Terpadu Surabaya - Surabaya, Indonesia

(2023-09 - 2023-12)

• Delivered weekly pre-lab tutorials to Engineering Faculty students and graded timed (45-minute) assignments in coordination with senior teaching staff.

Bachelor of Informatics Engineering - Informatics Engineering - Institut Sains dan Teknologi Terpadu Surabaya (ISTTS) (2021-08 - 2025-11)

High School Diploma in Science - Science - SMAK St. Agnes (2018-07 - 2021-07)