Retail
POS System
A retail point-of-sale platform handling real-time sales transactions, receipt generation, discounts, and integrated card and cash payment workflows.
// available for freelance work
Eugene John Arellano
AI-Augmented Full Stack Developer
Results-driven software professional with 13+ years delivering high-quality, innovative enterprise solutions — aligning clean technical execution with real business value.
13+
years of experience
21+
project domains
4
pro certifications
GMT+8
remote & async ready
// about
I build enterprise-grade software that's clean, reliable, and aligned with the business it serves — across the full stack, from database to UI.
Over more than 13 years I've delivered solutions across retail, healthcare, real estate, travel, finance, and beyond. My focus is on solid architecture and maintainable code — applying SOLID principles, clean architecture, and modern .NET — while embracing AI-augmented workflows to ship faster without cutting corners. I'm committed to continuous learning and staying ahead of emerging technologies, so the systems I build today are ready for tomorrow.
// expertise
A complete, modern toolkit
Thirteen years of hands-on engineering across architecture, cloud, data, and the full front-to-back stack.
Architecture & Practices
22 competencies
SOLIDDRYKISSYAGNIDesign PatternsClean ArchitectureVertical SliceModular MonolithMicroservicesMonolithOOPOODOWASPRESTfulUnit TestingAgileScrumMVC PatternN-Tier / LayeredResilience PatternsIdempotencyAzure
Cloud — Microsoft Azure
6 services
Azure App ServicesAzure SQL DatabaseAzure FunctionsAzure Blob StorageApplication InsightsAzure DevOps
Data, DevOps & Tooling
21 tools
GitGitHubAzure DevOpsBitbucketGitHub CopilotCursorClaudePowerShellSQL ServerMSSQLT-SQLAzure SQLEF CoreEntity FrameworkLINQDapperMediatRWolverineVisual StudioVS CodeSQL
Frontend & Backend
19 technologies
C#.NET Core.NET FrameworkASP.NET CoreASP.NET MVCASP.NETWeb APIRESTful APIAPI DesignWinFormsAngularVue.js 3TypeScriptJavaScriptjQueryChart.jsBootstrap 5HTMLCSS
// selected work
Projects across the years
A breadth of real-world systems delivered across industries — from point-of-sale and logistics to healthcare, real estate, travel, and insurance.
Retail
Cloud POS System
A cloud-native point-of-sale solution with multi-branch synchronization, offline-first resilience, and centralized sales reporting across all locations.
Retail
Inventory System
Real-time stock control with automated low-stock alerts, batch and SKU tracking, supplier management, and intelligent reorder automation.
Logistics
Warehouse System
A logistics and fulfillment system with bin-location tracking, optimized pick-and-pack routing, and coordinated dispatch operations.
E-Commerce
E-Commerce System
A full online storefront with product catalog, shopping cart, secure checkout, and complete order and fulfillment management.
Finance
Payroll System
An automated salary computation engine covering taxes, statutory deductions, payslip generation, and end-to-end payroll compliance.
HR
HR Management System
Centralized employee records, leave and attendance tracking, performance reviews, and streamlined onboarding workflows.
Scheduling
Appointment Scheduling
Calendar-driven booking with automated reminders, resource allocation, and conflict-free scheduling for staff and clients.
Operations
Queuing System
Customer flow management with digital ticketing, live queue displays, counter routing, and wait-time analytics.
Travel
Airline Booking & Reservation
Flight search, fare and seat management, reservation workflows, and booking confirmation across complex multi-leg itineraries.
Hospitality
Hotel Reservation System
Room availability, rate and inventory management, a real-time booking engine, and guest profile handling for hospitality operations.
Events
Event Ticketing System
Event setup, seat and ticket allocation, QR-coded ticket issuance, and real-time entry validation at the gate.
PropTech
Property Listing & Search
Real estate listings with advanced filtering, map-based search, saved searches, and rich, detailed property pages.
PropTech
Rental Management System
Lease lifecycle tracking, automated rent collection, maintenance requests, and self-service tenant portals.
PropTech
Tenant Screening Tools
Applicant background checks, credit and history evaluation, and risk scoring to support confident leasing decisions.
HealthTech
Electronic Health Records (EHR)
Secure patient records, clinical documentation, and care workflows built with healthcare data privacy and compliance in mind.
HealthTech
Medical Monitoring System
Real-time monitoring of patient vitals with threshold-based alerts, live dashboards, and instant clinician notifications.
EdTech
Library System
A catalog and circulation platform managing member records, borrowing and returns, due-date reminders, and fast title search.
EdTech
Online Examination & Assessment
Secure online exam delivery with question banks, automated grading, anti-cheating safeguards, and performance analytics.
Modernization
Legacy System Modernization
Re-architecting aging monolithic applications into modern .NET, clean architecture, and cloud-ready solutions — without disrupting operations.
Insurance
Insurance Systems
Policy administration and complex-risk handling across auto, homeowners (including wildfire-prone areas), construction, real-estate, and financial insurance.
// credentials
Certified & qualified
Microsoft and GitHub certifications backing real-world delivery, grounded in a computer science foundation.
Azure Data Fundamentals
Microsoft Certified · DP-900
Azure Fundamentals
Microsoft Certified · AZ-900
Azure AI Fundamentals
Microsoft · AI-900
GitHub Copilot
Certified · GH-300
BS in Computer Science
STI College — Ortigas Cainta
Philippines
A computer science foundation underpinning 13+ years of hands-on, production software engineering.
// contact
Let's build something solid.
Have a project in mind or a system that needs modernizing? I'm available for freelance work and happy to talk through what you need.
Email
ej@ejarellano.com
Phone · WhatsApp · Viber
+63 917 876 8073
LinkedIn
in/ejm-arellano
Based in
Rizal · Pasig · Quezon City · Metro Manila, PH
Send a message
Tell me about your project and I'll get back to you by email.