Portfolio

Hi, I'm Zefanya

Full Stack Developer

A dedicated software developer (WEB, Desktop App, Mobile App) with expertise in ASP.NET, C#, VB, Blazor, SQL Server, and MAUI. Currently established in the healthcare IT sector, while available for freelance opportunities.

View Projects Contact Me

Experience Since: 2017
Projects Completed: 15+
Stack: .NET

Tech Stack

Backend

ASP.NET Web Forms
ASP.NET MVC
Blazor Server
Blazor WASM
C#
VB.NET

Database & Cloud

SQL Server
T-SQL
SSRS
Azure
IIS

Mobile & Frontend

.NET MAUI
Xamarin
Bootstrap
JavaScript
HTML / CSS

About Me

I am a Full Stack Developer currently working in Hospital IT, developing and maintaining healthcare information systems. With experience in healthcare IT, I understand the importance of reliable, secure, and user-friendly systems.

Outside my main job, I'm open to freelance opportunities, from web applications, management systems, to mobile apps. I'm committed to delivering high-quality solutions tailored to client needs.

Domain Expertise

Healthcare IT Hospital Information System, EMR, Billing

Business Applications ERP, Inventory, POS, Payroll

Mobile Development .NET MAUI cross-platform apps

Web Applications ASP.NET, Blazor, REST API

Recent Projects

View All

2026

LexGo - AI for Contract Review

I built LexGo, an AI-powered contract review web application that helps users understand a contract's risks before signing it. I designed a pipeline that extracts text from PDF/DOCX documents, analyzes clauses with a Large Language Model, and classifies risk (high/medium/low) with plain-language explanations and negotiation recommendations. The main challenge I solved was legal grounding. I designed a Retrieval-Augmented Generation (RAG) system that anchors every analysis to a curated Indonesian legal Knowledge Base. I built the process that splits legal documents into individual articles, embeds them into vectors, and searches them semantically (cosine similarity) so the AI cites real legal grounds instead of hallucinating them. I also implemented a contract Q&A chatbot, a wallet/balance system, and consultation booking with a Legal Team.

ASP.NET. C# SQL SERVER

2026

Hospital Application for Android & iOS Mobile

I developed and launched an integrated mobile application (super-app) for patient healthcare services, designed to fully digitize the patient journey. This application provides a one-stop system that includes independent online clinic registration, real-time laboratory test result monitoring, direct access to radiological documents and images, along with various other essential services to streamline accessibility and improve hospital patient satisfaction.

iOS Android MAUI .NET C#

2026

Indonesian Pentathlon Score Management Website (Asian Pentathlon Championship 2026)

Entrusted by the Indonesia Pentathlon sports committee to design and develop a web-based computational and score management system for national-scale Pentathlon championships. This system is specifically engineered to process competition data in real-time, ensuring the highest level of transparency, absolute precision in point calculation, and result integrity for both athletes and stakeholders.

ASP.NET. C# SQL SERVER

2025

Employee Attendance Android & iOS Mobile Application v.2

I develop the employee attendance application into a centralized super-app focusing on operational fluidity and user experience (UI/UX). This application encompasses precise attendance tracking, letter administration management, a company information/announcement center, and an innovative automated meal voucher disbursement system based on a 7 hour work time validation to facilitate seamless cashless transactions within the canteen area.

iOS Android MAUI .NET C#

2022

Website for Nursing Care Plan/NCP

I designed and developed a web-based Nursing Care Plan (NCP) information system aimed at digitizing over 200 conventional clinical forms into a single integrated platform. This innovation effectively facilitates nurses in conducting paperless medical documentation, minimizing the risk of manual data entry errors, and significantly accelerating patient healthcare workflows. This website has been applied in more than 7 hospitals.

ASP.NET. C# SQL SERVER

2021

Website for e-Prescription

I designed and developed a web-based electronic prescribing (e-Prescription) system that integrates in real-time with the pharmacy unit's information system. This innovation drastically accelerates the medication service workflow, minimizes the risk of patient safety incidents due to manual prescription misreads (medication errors), and automatically implements validation rules and prescription restrictions in strict accordance with BPJS Kesehatan regulatory standards. This website has been used in more than 7 hospitals

ASP.NET. C# SQL SERVER

Let's Work Together

Have a project in mind? I'm ready to help turn your ideas into functional, high-quality applications.

WhatsApp Email Me