My experience spans business-critical systems, legacy modernization, modern web applications, and emerging AI technologies.
Most recently at SparkFire LLC, I maintained and extended a large production application for the HVAC industry, modernized parts of its
legacy stack, contributed to machine-learning workflows deployed through AWS SageMaker, and developed an MCP server for AI-assisted reporting.
Previously, as an Information Systems Analyst III at the Department of Social Welfare and Development – CAR, I led and built internal systems
supporting HR, finance, planning, learning and development, reporting, and other operational workflows.
Alongside my professional work, I've also built independent products and applications, including TaxZed, an accounting SaaS for the
Philippines, and Word Zoo, a mobile word game.
SparkFire LLC
PHP Senior Developer · –
Client work under NDA, so there are no screenshots, source code or identifying details.
A large production application for a client in the HVAC industry, built on a legacy PHP/Zend, JavaScript/jQuery, MySQL and MongoDB stack,
plus new applications for other SparkFire clients.
What I did
Maintained and extended the HVAC client's large production application, working within its established legacy codebase.
Diagnosed and fixed production issues, and optimized PHP code and database queries for performance and maintainability.
Maintained existing functionality built with PHP, Zend, JavaScript, jQuery, MySQL and MongoDB.
Gradually modernized parts of the legacy front end with JavaScript ES6, keeping it compatible with the existing application.
Built new functionality in React wherever a feature didn't have to fit the legacy front-end architecture.
Worked on new client applications in Laravel and React.
Built, with AI assistance, an HVAC balance-point machine-learning system prepared for deployment on AWS SageMaker:
classical and neural-network models, model comparison, feature correlation, feedback and empirical balance-point analysis.
Built, with AI assistance, an MCP server in NestJS that lets Claude work with SparkFire clients' reporting workflows.
Worked through traditional software engineering, writing and debugging code myself with documentation, Google and Stack Overflow,
until adding AI-assisted development to my workflow in 2026.
Impact
Helped keep a long-running production system stable while continuously improving and extending it, instead of requiring a complete rewrite.
The work ran from bug fixes and database optimization to React features, machine-learning infrastructure and AI-enabled reporting tools.
New applications for other clients rounded it out: maintaining business-critical legacy systems on one side, and building modern
applications from the ground up on the other.
PHP
Zend Framework
JavaScript (ES6)
jQuery
React
Laravel
NestJS
MySQL
MongoDB
AWS SageMaker
Machine learning
MCP
Claude
TaxZed
Independent product · Accounting SaaS for the Philippines · 2025–Present · in closed beta
A multi-tenant bookkeeping SaaS that automates VAT calculation and accounting entry generation for small Philippine businesses.
Most bookkeeping tools aren't built around local tax rules, so TaxZed's accounting and VAT workflows were designed around them from the start.
My role
Full-stack development: Laravel back end, React front end, database design, and deployment on DigitalOcean.
What I built
A multi-tenant expense and revenue ledger with automatic VAT from VAT-inclusive totals, calculated on the server rather than trusted from the browser.
Accounting entry generation that locks a month's transactions into an accounting period, with controlled administrator unlocking for corrections.
A chart of accounts seeded from BIR standard codes and shared across tenants.
Supplier management with TIN tracking, and inline supplier creation from the expense workflow.
BIR form records for 2550M and 2550Q, tied to accounting periods.
A superadmin panel with company impersonation, feedback triage and controlled period unlocking.
Technical challenges
Exact VAT arithmetic: the base amount comes from the VAT-inclusive total and the tax is the remainder, so every transaction reconciles without rounding drift.
Multi-tenancy in one database: a reusable BelongsToCompany trait applies a global Eloquent scope and fills in company_id automatically.
Authentication across origins: Sanctum, CORS and CSRF configured so the separate React front end and Laravel back end work together securely.
Keyboard-first entry: shortcuts like Alt+S and Alt+N and arrow-key table navigation for fast, repetitive bookkeeping.
Result
Live at app.taxzed.com in closed beta, with real testers entering bookkeeping data. Expense and revenue entry, VAT computation,
accounting generation and BIR form records all work, and development continues ahead of the public launch.
Independent product · Mobile word game for Android · 2026 · in Google Play closed testing
A word-guessing puzzle game where players rescue animals by spelling words to defeat the villain, Dr. Snuggles.
Instead of disconnected puzzles, the levels form a story: beat the villain, rescue animals, and unlock new worlds.
My role
Product vision, game design, level content, art direction, monetization and in-app purchase strategy, Google Play setup, QA and
technical direction. I used AI-assisted development for code implementation, architecture exploration and technical problem-solving.
What I built
10 themed worlds with 400+ levels of single-word and multi-word phrase puzzles.
Flame-powered gameplay: animated animals, villain reactions, hearts, countdown timers and interactive game states.
Banner, skippable interstitial and rewarded ads, with rewarded ads for continues.
Cloud save and accounts with Firebase and Google Sign-In, so progress follows players across devices.
Quests, daily bonus streaks, leaderboards, coins, hints and hint packs.
Google Play in-app purchases for eight planned products across coins, hint packs and ad-free tiers.
Technical challenges
Dynamic phrase layout: a two-pass word-packing approach sizes the letter slots to the screen and phrase length, without overlapping the on-screen keyboard.
Ad frequency that survives navigation: the "every three levels" counter lives in a persistent AdService singleton instead of screen state.
Safe async game callbacks: lifecycle guards on callbacks like onWin and onLose, so delayed calls can't touch disposed widgets.
Result
Feature-complete in about two months and in Google Play closed testing with 12+ testers. Gameplay, progression, cloud save, ads and
in-app purchases are in place; the public release is waiting on Google Play's review and launch process.
Flutter
Flame
Dart
Firebase Auth
Cloud Firestore
AdMob
Google Play Billing
Provider
POWER Grid System
Team lead and main programmer · DSWD – CAR
Pillars for Optimum Welfare, Empowerment and Revitalization: a performance tracking system for the field office's planning department.
It shows which programs and sections are behind their physical or financial targets.
What I did
Led the team and was the system's main programmer.
Coded all the algorithms and calculations behind the main dashboard and the statistics page.
Designed and created the database.
Gave teammates technical help and code reviews, so they understood the flow and the data being fetched.
Built the sign-in page, libraries for encoding prerequisite data, reports and statistics, an awards feature and the dashboard.
Impact
The planning department can easily track which programs and sections are behind their financial or physical targets.
It also motivated programs to hit their targets early, since early achievers are rewarded, and that shows in the system.
PHP
CodeIgniter
Vue.js
JavaScript
Bootstrap
CSS
HTML
MySQL
Git
Sign-in.The power grid on the public website: each pillar's accomplishment against target.Statistics: targets against accomplishments.Performance governance assessments.Targets and accomplishments by strategic priority.
EPIC
Team lead and main developer · DSWD – CAR
The Employees' Portal and Information Center is the department's human resources information system.
It's the department's most visited system, and where employees' data is stored.
What I did
Led the team as the main developer.
Built the Performance Management (PMS) module for employee performance reviews, coding its process flow in PHP and CodeIgniter: create, update, delete, view, validation, filtering and everything else its sub-modules needed.
Designed the MySQL database.
Wrote API calls, DOM manipulation and form validation in JavaScript and Vue.js, and built the interface with Bootstrap and CSS.
Fixed bugs, reviewed code, and wrote algorithmic helpers for other modules: Rewards and Recognition, Learning and Development, and the Recruitment Selection Plan.
Deployed production updates with Git, and used it to keep the team's work free of conflicts.
Impact
EPIC lightened the Human Resources division's workload: less paper printed, ratings analysed by the system,
each employee's information encoded once, and reports generated automatically.
PHP
CodeIgniter
JavaScript
Vue.js
jQuery
Bootstrap
CSS
HTML
MySQL
Git
Performance commitments: key result areas and indicators.Commitments by semester, with approval status.Accomplishment report.Creating and listing accomplishment reports.Client statistics.
ABCIS
Accounting, Budget, and Cash Information System · DSWD – CAR
Handles the division's allocations, obligations, disbursements and payments, its reports, and document tracking.
What I did
Oversaw the deployment, and enhanced and adapted the code to fit the region's process flow.
Built the features employees needed: creating and updating data, the relationships between records, and report generation.
Coded it in PHP and Laravel with Vue.js on MySQL, and designed it with Tailwind CSS.
Began rebuilding the system with a React front end.
Impact
The Financial Management Division prints less, sends reports to the central office in one click, and can see where each document is.
Tracking allocations and liquidations got easier, and employees work less overtime.
PHP
Laravel
Vue.js
React
Tailwind CSS
Bootstrap
JavaScript
MySQL
Home: announcements and organizational outcomes.Disbursement vouchers, with overdue ones flagged.Creating a disbursement voucher.Cash receipts record.Sign-in.
HITECH LXP
DSWD – CAR
Part of Field Office Cordillera's digital transformation strategy: an online learning hub that accelerates its talent development
and supports the professional development of its personnel and intermediaries.
What I did
Created the project's modules: course content management, examinations, feedback, reporting, certificate generation, course posting and enrollment, among others.
Built it with PHP, Laravel, JavaScript and jQuery, then moved the front end to Vue.js, with CSS and Bootstrap, on a MySQL database.
Impact
The platform helped the capacity-building section generate its reports, and lets the region teach local government units online.
Keeps track of the maintenance done on the department's computers, automated in preparation for ISO certification.
What I did
Led the team as its systems analyst.
Spearheaded the features: sign-in with Active Directory, content management for maintenance prerequisites, the maintenance form, and reporting.
Wrote the logic that takes data from API calls to the back end and presents it on the page.
Impact
The system was deployed, demoed to end users, and put to use by one section of the department.
PHP
Laravel
Vue.js
React
Tailwind CSS
CSS
MySQL
Git
Maintenance tasks and sub-tasks.Adding a maintenance task.Equipment type library.
MINT ERP
Main back-end developer · Freelance for DGoodman Corp
An enterprise resource planning system, delivered to a client company that bought it and uses it internally.
What I did
Worked as the main back-end web developer.
Coded the features: a dynamic organizational chart, e-approval (ticketing), project management with its calculations and Gantt charts,
and employee management across users, user levels and departments, all with related data.
Wrote the back end in PHP with CodeIgniter, built the interface with JavaScript, jQuery, CSS and Bootstrap, and managed code with Git.
Impact
Delivered successfully: the company bought the system and uses it internally.
PHP
CodeIgniter
JavaScript
jQuery
Bootstrap
CSS
Git
Dynamic organizational chart.E-approval requests.Project details and task progress.Project Gantt chart.User management, switched to Korean.
Payroll System
Software Developer · Beijing Bangnishuo Internet Education Technology Limited
An in-house system that tracks payroll for all employees.
What I did
Built the relational database, API calls, algorithms, calculations and a simple interface.
Connected two systems on different servers, since payroll relied on the company's evaluation system.
Delivered every feature the project manager asked for, using a JavaScript library for faster development.
Impact
Delivered successfully. Payroll became faster and easier to produce, and the system had an impact on employees' performance.
PHP
CodeIgniter
Laravel
JavaScript
jQuery
Vue.js
React
Bootstrap
HTML
MySQL
Colleagues' and clients' names in screenshots are blacked out.
I'm a software engineer with 10 years of professional experience building, maintaining and modernizing web applications and business systems,
across the whole lifecycle: business requirements, database design, features, production support, performance, and the gradual
modernization of legacy code.
As an Information Systems Analyst III at the Department of Social Welfare and Development – CAR (2019–2022), I led and built internal systems
for human resources, finance, reporting, learning and development, and planning. I worked closely with end users to turn real business
processes into software, and owned development, database design, deployment, maintenance and technical guidance.
At SparkFire LLC (2022–2026), I maintained and extended a large production application for a client in the HVAC industry, on a legacy
PHP/Zend, jQuery, MySQL and MongoDB stack: fixing production issues, optimizing code and queries, adding features, and modernizing the
front end with ES6 and React without a costly rewrite. Later I built, with AI assistance, an HVAC balance-point machine-learning system
for AWS SageMaker and an MCP server in NestJS that lets Claude work with client reports, and contributed to new Laravel and React
applications for other clients.
Until early 2026 I worked the traditional way: writing and debugging code myself, with documentation, Google and Stack Overflow.
Now I use AI assistance where it adds leverage, while architecture, requirements, validation, code review and engineering decisions
stay under human direction.
Much of my work is under NDA, so I can't publish client code, data or screenshots. This portfolio shows the problems I worked on, the
technologies, my responsibilities, and the software I can show.
Today I'm bringing that experience into our software studio, DGoodman Corp, where we help businesses build new applications,
modernize legacy systems, rescue troubled projects, and keep software running with a dependable long-term engineering partner.
Experience
NowDGoodman CorpOur software studio: new applications, legacy modernization, project rescue and long-term maintenance.TaxZed · Word Zoo
