Case Studies

Projects & case studies

Five systems spanning enterprise authentication, education technology, recruitment and digital banking. Each case study covers the problem, my responsibilities and the engineering decisions behind the delivery.

Enterprise Authentication & Authorization

SSO System — Centralized Authentication Service

Designed and engineered a centralized Single Sign-On (SSO) authentication service to provide unified authentication across multiple applications within an ecosystem.

Key responsibilities

Designed centralized SSO architecture.
Developed authentication and authorization REST APIs.
Implemented JWT-based authentication.
Integrated Basic Authentication for service-to-service communication.

Technical highlights

Centralized authentication across multiple applications.
Designed for a stated capacity of up to 1 million concurrent users.
Consistent authentication across integrated platforms.

Stack

Education Technology Platform 2022 — 2026

LuarSekolah Platform

Developed and maintained backend infrastructure for an education technology platform providing online classes, webinars, and digital learning services.

Key responsibilities

Architected backend infrastructure.
Established reusable API foundations.
Designed and developed REST APIs for web and mobile applications.
Designed and optimized MySQL databases.

Technical highlights

Reusable API foundation shared by web and mobile clients.
Redis caching layer applied to high-traffic read paths.
Payment gateway and messaging integrations handled inside the platform backend.

Stack

Recruitment & Career Platform 2022 — 2026

Japan Tech Career Platform

Built core backend API services for a recruitment and career platform connecting users with career opportunities in Japan.

Key responsibilities

Built backend API services from scratch.
Designed RESTful API endpoints.
Managed MySQL database structures.
Integrated third-party recruiting tools.

Technical highlights

Backend API layer designed and delivered from an empty codebase.
Third-party recruiting tooling integrated behind stable internal endpoints.
Endpoint level access control enforced through JWT authentication.

Stack

Enterprise Digital Banking 2019 — 2021

OCBC NISP — Internet & Mobile Banking

Contributed to enterprise-grade Internet Banking and Mobile Banking systems supporting critical financial transactions.

Key responsibilities

Developed backend services using Java and Spring Framework.
Built RESTful APIs.
Implemented authentication and authorization using Spring Security.
Designed and optimized Oracle database schemas and stored procedures.

Technical highlights

Backend services built for high-integrity financial transactions.
Spring Security used to enforce authentication and authorization rules.
Query, schema and stored procedure tuning on Oracle Database.

Stack

Enterprise BackOffice & Billing 2015 — 2016

Paybil — BackOffice & Billing Management System

Contributed to the development of Paybil's BackOffice and Billing Management System.

Key responsibilities

Developed core application logic.
Participated in requirements gathering.
Supported software testing.
Prepared automated testing scripts.

Technical highlights

Delivered billing and back office workflows from requirements through deployment.
Automated test scripts prepared to validate core billing logic.
Direct collaboration with stakeholders during requirements gathering.

Stack

Have a system that needs to scale?

From API design to database tuning and secure authentication, I can help you ship backend work that lasts.

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