Mobile Engineer at MIAWest Java, Indonesia

Building reliable mobile apps, from UI to backend.

I’m Fajar, a mobile engineer with 5+ years of experience in Flutter and native Android. I ship complete products — cross-platform apps, the APIs behind them in NestJS, Deno and TypeScript, and AI features powered by GPT and Gemini.

View my work
years shipping mobile apps
5+
product companies
3
MIA App Store rating
5.0★
across 36 open-source repos
96★
Rotate app home screen with the next flight, weekly pay and pilot rating
MIA app AI interview practice screen
MIAAI platform · iOS & AndroidRotateFlight sim careers
Shipped to production at
  • MIA
  • Dipay
  • TrawlBens
Selected work

Products in the hands of real users

Two live apps on iOS and Android — one I build at work, one personal portfolio project — plus open-source libraries I maintain.

Mobile app + backendJul 2025 — PresentiOS · Android

MIA — Migran Indonesia Asisten

An AI-powered platform that helps Indonesian migrant workers find safe, legitimate jobs abroad and supports them through the whole journey, from registration to remittance.

  • AI interview practice and soft-skills preparation
  • Digital registration with document verification
  • Real-time placement tracking, training and remittance

My roleI build both sides — the cross-platform mobile app and the backend services and APIs behind it, including the GPT and Gemini integrations that power its AI features.

App Store rating
5.0 ★
Google Play installs
1K+
Visit migran.ai App StoreGoogle Play
MIA welcome screen introducing the MIA assistant
MIA AI interview practice: real interview simulation, instant feedback and progress tracking
MIA readiness score screen celebrating a 15% score increase
Rotate career screen: rank progress to Captain, pilot rating, airline contract and licenses
Rotate flight debrief with a score of 87, a −142 fpm touchdown and landing metrics
Rotate live flight screen in cruise at FL360 with a route map and flight events
Personal projectSince Sep 2026iOS · Android beta · Windows

Rotate — fly like it counts

A personal project I build on my own time. Rotate turns Microsoft Flight Simulator 2020 and 2024 into a structured airline career: get hired by virtual airlines, fly assigned routes, get a detailed debrief on every landing and climb the ranks from Second Officer to Training Captain.

100-point scoring
Shared across the phases you actually fly
Live tracking
Phone app + PC Bridge telemetry
Career mode
Type ratings, airline contracts, ranks
Real dispatch
SimBrief plans, live METAR / TAF

Built end to end as a portfolio piece — mobile apps, Windows PC Bridge and local payments (cards, GoPay, OVO, DANA).

Visit flightrotate.com 30-day free trial · from $2.99/mo
Rotate PC Bridge for Windows: pilot dashboard with employment contract, type ratings, rating trend, credits and recent flights
PC Bridge for Windows — reads the simulator and streams live telemetry to the phone.

Open-source Android libraries

Small, focused Kotlin components for common UI and data patterns.

All repositories
Experience

Five years of shipping to production

From migrating a logistics app to native Kotlin, to rebuilding a fintech app in Flutter, to owning both mobile and backend for an AI platform today.

90%
increase in app responsiveness after the native rewrite at TrawlBens
80%
less system instability in the same migration
Education
SMK Garuda Nusantara
Full profile on LinkedIn

  1. Mobile Engineer

    MIA · Migran Indonesia Asisten · Full-time
    Jul 2025 — Present

    Building the MIA mobile app and its backend end to end — AI interview prep with GPT and Gemini, document verification, placement tracking and financial services for Indonesian migrant workers.

    • Flutter
    • NestJS
    • Deno
    • TypeScript
    • OpenAI GPT
    • Google Gemini

  2. Mobile Engineer

    Dipay · Full-time · Jakarta
    May 2022 — Jun 2025
    • Rebuilt the Dipay app from native Kotlin & Swift (v2) into Flutter (v3) with a complete UI overhaul on Clean Architecture.
    • Shipped Loans, Multi-Outlet Support and Dynamic QR Code features in the Dipay Bisnis app.
    • Covered every feature function with unit tests for quality, stability and reliability.
    • Built CI/CD workflows with CircleCI and Fastlane that streamlined deployment for 2 applications and were adopted by 2 developers, improving team collaboration and productivity.
    • Dipay home screen with the wallet balance and top-up and bill shortcuts
    • Dipay spending statistics for the month, grouped by category
    • Dipay Bisnis merchant home with balance, QR code and recent transactions
    • Dipay Bisnis QRIS code that customers scan to pay the merchant
    From the App Store: Dipay · Dipay Bisnis
    • Flutter
    • Kotlin
    • Swift
    • Clean Architecture
    • CircleCI
    • Fastlane

  3. Android Developer

    TrawlBens · Contract · Jakarta
    Feb 2021 — May 2022
    • Migrated the TrawlBens app from Cordova to native Android (Kotlin): 90% more responsive, 80% less instability.
    • Designed and built TrawlPack with the Google Maps API for pickup scheduling and real-time driver tracking.
    • Built real-time in-app chat over WebSocket to improve package tracking.
    • Kotlin
    • Android SDK
    • Google Maps API
    • WebSocket
Skills

Mobile first, end to end

Mobile

Cross-platform and native apps, from first screen to store release.

  • Flutter
  • Dart
  • Kotlin
  • Swift

Backend

The APIs and services the apps run on.

  • TypeScript
  • NestJS
  • Deno
  • REST APIs
  • WebSocket
  • Payments

AI & integrations

Language models and third-party platforms wired into real features.

  • OpenAI GPT
  • Google Gemini
  • Google Maps API

Engineering practice

Habits that keep a codebase shippable as it grows.

  • Clean Architecture
  • Unit testing
  • CircleCI
  • Fastlane
Contact

Let’s build something people rely on.

Open to conversations about mobile engineering, AI-powered products and new opportunities.

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