Open to backend and full-stack roles

Backend Engineer · Jakarta, Indonesia

Building backends that keep the business moving.

Backend engineer in Indonesia’s automotive sector. I build and run the APIs, integrations and cloud services behind a large vehicle auction platform, and before that I connected fleet vehicles to the cloud.

auction-platform-api

$ curl -X POST /api/v1/auctions/1001/bids

-H "Idempotency-Key: 7f3c…"

-d '{"amount": 147000000}'

HTTP/1.1 201 Created · 38 ms

{

"status": "live",

"currentPrice": 147000000,

"minimumNextBid": 147500000,

"youAreHighest": true,

"extended": false

}

Crafting backends people can rely on.

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The philosophy

“Good backend work is mostly invisible. Auctions close on time, trucks show up on the map, the login just works, and nobody has to think about why.”

— Imron Athoriq Firjatulloh

The

Philosophy

Scroll to expand

01 About

Engineering for operations

I am a backend engineer at PT Serasi Autoraya, part of the Astra International group, where I maintain and extend the services and APIs of IBID, the company’s automotive auction platform. My recent work covers authentication (moving users to Azure credential-based login), API performance, and internal platforms that replace manual work.

Earlier I built cloud IoT services that move vehicle telemetry through Azure IoT Hub and Service Bus into a Flutter tracking app, and Laravel features for procurement. I studied both Information Systems and Instrumentation Engineering, so I am comfortable anywhere from a database index to an ESP32 on a breadboard.

I care about turning business requirements into systems that are simple to operate, and I work in Scrum teams with developers, QA and the operations people who use what we build.

Impact at a glance

30%

fewer login issues after moving to Azure credential-based login

20%

faster backend after refactoring services and APIs

25%

less manual work through internal operations platforms

35%

more efficient telemetry processing on Azure IoT

40%

clearer budget reporting with plan-vs-actual dashboards

3.89

GPA in Information Systems, Politeknik STMI Jakarta

What I do



Backend & API engineering

REST APIs in Laravel and Express.js, designed for the edge cases: concurrency, retries, validation and clear errors.



Authentication & integration

Single sign-on with Azure credentials, JWT, and integrations between internal systems that used to rely on spreadsheets.



Cloud & IoT

Device-to-cloud pipelines with Azure IoT Hub and Service Bus, from the GPS tracker to the map in a mobile app.



Performance & reliability

Profiling slow endpoints, fixing N+1 queries and indexes, and Docker + Nginx set-ups that match production.

02 Selected work

Projects & case studies

Production work from my roles (described, as the code belongs to my employers), plus open-source and research projects you can read and run.

All

Backend

Cloud & IoT

Full stack

Research

Personal open-source project · Node.js · Express · 37 tests · Docker

A vehicle auction backend built around the hard parts of bidding: simultaneous bids, last-second sniping, retried requests and notifications that must never slow a bid down.

Try it in the live API playground below

02 / 10



Backend · 2025 – now

IBID: Azure Login & API Performance

Backend Developer · PT Serasi Autoraya (Astra International)

Authentication and performance work on IBID, an automotive auction platform that runs large-scale auctions every day.

Full stack · 2025 – now

Internal Operations Platforms

Backend Developer · PT Serasi Autoraya (Astra International)

Internal web platforms that replace manual, spreadsheet-driven processes for the operations teams around the auction business.

IoT Engineer Intern · PT Serasi Autoraya (Astra International)

Real-time fleet monitoring: GPS trackers send telemetry to Azure, an Express.js service processes it, and a Flutter app shows every vehicle on the map.

Sourcing Management System 2.0

Backend Developer Intern · PT Serasi Autoraya (Astra International)

Backend features for the second version of the procurement (sourcing) system, alongside work on the IBID auction platform.

Electronic Archive & Document Numbering

IT Planning & Budgeting Intern · thesis · PT Pertamina Hulu Indonesia

A web application for the IT division that issues document numbers automatically and keeps a searchable electronic archive.

IT Budget Plan vs. Actual Dashboards

IT Planning & Budgeting Intern · PT Pertamina Hulu Indonesia

Dashboards that compare planned and realised IT costs, so budget owners see deviations without assembling reports by hand.

Human Motion Detection with ESP32-CAM

Undergraduate thesis · Universitas Brawijaya

An embedded system that detects human presence with an LD2410 mmWave radar and sends a photo over Wi-Fi from an ESP32-CAM.

Banknote Authentication with Arduino

Project · Universitas Brawijaya

A low-cost tool that checks Indonesian Rupiah banknotes by measuring RGB colour intensity with LDR sensors.

Personal project · React Native · Expo Router

One React Native code base that is exported as a static website and also runs as an iOS and Android app, with a live playground for my backend API.

03 Experience

Where I’ve been

Mar 2025 — Present

Jakarta

Current

Backend Developer

PT Serasi Autoraya · Astra International

▸

Maintain and extend the backend services and REST APIs of IBID, the company’s automotive auction platform, which runs large-scale daily auction operations.

▸

Integrated Azure credential-based login into the authentication flow, cutting login-related issues by 30% and making sign-in more reliable.

▸

Refactored backend services and optimised API endpoints, improving system performance by 20%.

▸

Built and optimised internal operational platforms that reduced manual processes by 25%.

▸

Turn requirements from operations stakeholders into technical designs, and deliver them in Scrum with developers and QA engineers.

▸

Use AI-assisted engineering (Claude-based tooling) for debugging, refactoring and faster feature delivery.

Laravel

PHP

REST APIs

Azure

MySQL

SQL Server

Feb 2024 — Apr 2024

Jakarta

IoT Engineer Intern

PT Serasi Autoraya · Astra International

▸

Built a Flutter GPS tracking app for real-time fleet monitoring.

▸

Developed Express.js and MongoDB services that process vehicle telemetry delivered through Azure IoT Hub and Azure Service Bus.

▸

Improved telemetry delivery reliability and event-processing efficiency by 35% with a scalable cloud architecture.

▸

Researched and prototyped connected-vehicle systems for fleet and rental operations, and designed device communication workflows with the engineering team.

Flutter

Express.js

MongoDB

Azure IoT Hub

Azure Service Bus

Jul 2023 — Dec 2023

Jakarta

Backend Developer Intern

PT Serasi Autoraya · Astra International

▸

Developed and optimised backend features for the IBID auction platform in Laravel (PHP).

▸

Contributed to Sourcing Management System 2.0, speeding up procurement workflows by 20%.

▸

Reduced recurring bugs by 25% through debugging, performance fixes and code optimisation.

▸

Set up Docker and Nginx for local development so it behaved like the deployed environment.

Laravel

PHP

MySQL

Docker

Nginx

Sep 2021 — Feb 2022

Jakarta

IT Planning & Budgeting Intern

PT Pertamina Hulu Indonesia

▸

Built budget dashboards comparing planned and actual IT costs, improving reporting clarity and decision-making efficiency by 40%.

▸

Built an electronic archive and document numbering web app in CodeIgniter 4, reducing manual document processing by 30% (later my thesis).

▸

Automated data processing for IT budgeting and reporting, and produced communication material for company-wide initiatives.

CodeIgniter 4

PHP

MySQL

Data visualisation

04 Foundations

Education & skills



Bachelor of Instrumentation Engineering

Universitas Brawijaya · Malang

Sep 2020 – Jan 2025 · GPA 3.47 / 4.00

Microcontrollers, PLC, embedded systems, electronics, instrumentation systems. Thesis: human motion detection with ESP32-CAM and LD2410 radar.



Bachelor of Information Systems

Politeknik STMI Jakarta · Jakarta

Aug 2018 – Dec 2022 · GPA 3.89 / 4.00

Database design, ERP systems, business process analysis, UI/UX, Java, Python, PHP, Oracle Database. Thesis: electronic archive system in CodeIgniter 4.



Programming Team Lead

PyRoC (Physics Robotic Club), Universitas Brawijaya · Feb 2023 – Dec 2023

▸

Led the programming division for the club’s robotics projects.

▸

Planned and assigned tasks, and kept the team on its delivery timelines.

▸

Worked with mechanical and electronics members to ship working robots.

Technical skills

Backend

PHP

Laravel

CodeIgniter 4

JavaScript

Node.js

Express.js

REST API design

Authentication (Azure, JWT)

Cloud & DevOps

Azure IoT Hub

Azure Service Bus

Docker

Nginx

Git

Databases

MySQL

SQL Server

Oracle Database

MongoDB

Mobile & IoT

Flutter

ESP32 / ESP32-CAM

Arduino

Embedded systems

Also

Python

Java

Agile & Scrum

Bizagi Modeler

ADempiere ERP

Certifications & training



Elements of AI

MinnaLearn · 2022



Machine Learning Developer

Digital Talent Scholarship · 2022



Data Visualization with Python

Cognitive Class · 2022



Database Design & Programming with SQL

Digital Talent Scholarship · 2021

05 Publications

Research & theses

Undergraduate thesis · 2024

Human Motion Detection System with Wi-Fi Photo Transmission Using ESP32-CAM and LD2410

Sistem Deteksi Gerakan Manusia dengan Pengiriman Foto melalui WiFi Menggunakan ESP32CAM dan LD2410

Imron Athoriq Firjatulloh · Universitas Brawijaya · Instrumentation Engineering

Supervisors: Drs. Hari Arief Dharmawan, M.Eng., Ph.D. · Prof. Agus Naba, S.Si., M.T.

Designs and tests an embedded monitoring system in which an LD2410 24 GHz radar detects human presence and motion, including people who stand still, and an ESP32-CAM captures a photo and sends it over Wi-Fi as evidence.

ESP32-CAM

LD2410 radar

Embedded systems

IoT



View in UB repository

Firjatulloh, I. A. (2024). Sistem deteksi gerakan manusia dengan pengiriman foto melalui WiFi menggunakan ESP32CAM dan LD2410 [Undergraduate thesis, Universitas Brawijaya]. Brawijaya Knowledge Garden. https://repository.ub.ac.id/id/eprint/235679/

Undergraduate thesis · 2022

Design and Development of an Electronic Archive Information System Using CodeIgniter 4 for the IT Division of PT Pertamina Hulu Indonesia

Rancang Bangun Sistem Informasi Arsip Elektronik Menggunakan Framework CodeIgniter 4 pada Divisi IT di PT Pertamina Hulu Indonesia

Imron Athoriq Firjatulloh · Politeknik STMI Jakarta · Information Systems

Analyses the IT division’s paper-based archiving and manual document numbering, then designs and builds a web-based electronic archive with automatic numbering, search and retrieval using CodeIgniter 4.

CodeIgniter 4

Information systems

Document management



Politeknik STMI repository

Firjatulloh, I. A. (2022). Rancang bangun sistem informasi arsip elektronik menggunakan framework CodeIgniter 4 pada Divisi IT di PT Pertamina Hulu Indonesia [Undergraduate thesis, Politeknik STMI Jakarta].

06 Writing

Notes on backend & full stack

Field notes from building auction, IoT and enterprise systems: authentication, performance, event-driven design and the tooling around them.



Full stack

27 October 2026 · 3 min read

One code base for web and mobile: building this portfolio with React Native and Expo

Why a backend engineer built a portfolio in React Native, how Expo Router exports it as a static website with real HTML and metadata, and how the live API playground talks to the backend.

Read article →



Backend design

20 October 2026 · 4 min read

Designing a bidding engine: concurrency, anti-sniping and idempotency

The rules behind a fair online auction and how to enforce them in code: optimistic locking, extending the close on late bids, safe retries and event-driven notifications.

Read article →



DevOps

21 July 2026 · 3 min read

Docker and Nginx for a PHP team: a local environment that behaves like production

A Compose set-up for Laravel with PHP-FPM, Nginx, MySQL and Redis, plus the details that cause most "works on my machine" bugs: versions, extensions, permissions and Windows file performance.

Read article →



Performance

2 June 2026 · 3 min read

Making a Laravel API 20% faster without a rewrite

Measure first, then fix the usual suspects: N+1 queries, missing indexes, over-fetching, offset pagination and work that belongs in a queue.

Read article →



Authentication

14 April 2026 · 4 min read

Adding Azure single sign-on to a Laravel platform without locking anyone out

How to move an established platform from passwords to Azure (Microsoft Entra ID) login: the OpenID Connect flow, matching existing accounts, a staged rollout, and the failures you will meet in production.

Read article →



Cloud & IoT

10 March 2026 · 3 min read

From GPS tracker to map: vehicle telemetry with Azure IoT Hub, Service Bus and Express.js

A practical architecture for fleet tracking: device identity, routing, consumers that survive duplicates and out-of-order data, storage for positions, and a mobile app on top.

Read article →

07 Live API

Try the backend

These buttons call my open-source Auction Platform API. Log in as a demo buyer, place a bid, break a rule and read the error. Every request is shown exactly as sent.

GET

List live auctions

Ending soonest first, reserve price hidden

GET

Auction detail

Current price, minimum next bid, time left

POST

Returns an HS256 JWT

POST

Place a valid bid

Logs in, reads the minimum, bids with an Idempotency-Key

POST