Story 01: AHMAD QOSAM AMRUL HAQ / FULLSTACK ENGINEER

Building robust fullstack solutions.

Fullstack Engineer dedicated to the craft of scalable systems. I specialize in translating sophisticated logic into seamless, global-scale products.

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The Vault

/ case-studies

Coffee Subscription Platform Migration & Optimization
01

Coffee Subscription Platform Migration & Optimization

Mission

Automate complex pricing updates and data migrations without disrupting the existing customer base or revenue flow.

Challenge

Managed the engineering lifecycle for the Subscription platform, utilizing event-driven microservices to integrate Node.js with Chargebee. Led system migrations and pricing updates for a 100k+ customer base, driving a 20% growth in sales.

NodeJSChargebeeGCPReact
Subscription Retention & Churn Recovery
02

Subscription Retention & Churn Recovery

Mission

Integrated a logic-based cancellation flow using Chargebee's retention suite, successfully deflecting 44% of potential churn and securing recurring revenue

Challenge

High revenue loss due to a lack of automated, personalized interventions during the customer cancellation process.

ChargebeeNode.jsGCPNext.js
Self-Service Promo & Campaign Integration
03

Self-Service Promo & Campaign Integration

Mission

Developed a Chargebee-based promo service that empowered marketing teams to launch independent subscription campaigns, significantly accelerating time-to-market for new promotions.

Challenge

Marketing agility was hindered by a dependency on engineering for every promotional launch, creating bottlenecks and delaying campaign timelines.

ChargebeeNode.jsGCP
Frictionless Authentication & Fraud Prevention
04

Frictionless Authentication & Fraud Prevention

Mission

Deployed a "Silent Network Authentication" (SNA) and Twilio 2FA framework for the Club Pret ecosystem. This implementation effectively mitigated widespread subscription fraud while maintaining a seamless, high-conversion login experience.

Challenge

Balancing the need for a robust defense against account takeovers and subscription fraud without introducing excessive "friction" (annoying steps) that could lead to user drop-off.

TwillioAuth0Node.jsGCP

Arsenal

01. frontend

  • React EST. 2018
  • TypeScript EST. 2019
  • Tailwind CSS EST. 2020
  • Next.js EST. 2020

02. backend

  • Node.js EST. 2020
  • Express.js / Fastify / Hono EST. 2020
  • PostgreSQL EST. 2025
  • Redis EST. 2022

03. devops

  • Docker EST. 2022
  • GCP EST. 2022
  • CI/CD Pipelines EST. 2022
  • Terraform EST. 2021

My stack is ever-evolving. I focus on the primitives of engineering: clean code, reliable testing, and high-quality user empathy.

Step 04: Connection

Let's build tomorrow.

I am currently accepting new challenges and creative collaborations. The first step of every great collaboration is a simple dialogue.

Digital Address

ahmadqosam@gmail.com

Base of Operations

Jakarta, Indonesia

Current Status

Available for Hire