Software Engineer

Dexter Fernandez

I'm a software engineer who builds the software businesses use every day: workflow automations, database and desktop systems, websites, and mobile apps. Tell me what you need and I'll tell you how I'd build it.

Start a project See my work

Available for freelance software projects

BS Computer Engineering, 2025

Services

What I can build for you

Desktop and database systems

Windows applications built with C# or Visual Basic on .NET, backed by SQL Server or Oracle, including legacy Access-to-SQL Server migrations and reporting.

Workflow automation

Scheduled n8n workflows that pull data from an API or a website and send it to Google Sheets or a database such as PostgreSQL, with run-status checks before results are saved.

Data collection tools

Scrapers and pipelines that collect, filter, score and export data, such as brands to review. See my Meta ads research tool below.

AI features

Add AI to your software system through language-model and vision APIs, such as automated recommendations or structured analysis based on your data.

Websites

Responsive websites for businesses and events, deployed to Vercel or Cloudflare Pages.

Mobile app MVPs

Flutter MVPs for Android and iOS with QR scanning, camera features, and offline support. I build and test for both platforms. I can hand over Android builds directly; installing an iOS build or publishing it to the App Store requires your Apple Developer account.

Projects

Software I've built

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HR Management System

A Windows HR system migrated from Access to SQL Server Express for a security-agency client.

A Windows HR system for a security-agency client, delivered through KodoGen Security Systems. I migrated the database from MS Access to SQL Server Express, updating more than 10,000 lines of VB.NET data-access code from OleDb to SqlClient and replacing Access queries with SQL Server views. I also built a two-table performance-appraisal workflow, case-sensitive login, data-grid record views, and Excel export for Looker Studio reporting.

Recent requests I delivered from the client's task lists:

Clearance records with result statuses, remarks and expiration tracking reports.
Employee status changes, medical records by type (Annual Medical, Pre-Employment, Pre-Permanency, and Neurological), commendations, and suspension date ranges for violations.
A monthly disposition report record for inventory management.
Activity logs that record every new, edit, and delete action, plus a yearly view of performance evaluations.

Flow: MS Access (OleDb) → SQL Server Express (SqlClient) → Windows Forms (.NET) → Excel export → Looker Studio reporting.

Visual Basic (.NET) · SQL Server Express · Windows Forms · Excel export · Looker Studio

Automation · runs locally · Python and n8n · MVP

AdsRadar

Research workflow that screens Meta advertisers, scores brands, and updates a Google Sheet.

The tool collects ads through the Meta Ads Library API and a web scraper, checks advertisers' stores and reviews, filters by topic, and scores brands for review.

The n8n workflow is scheduled for Mondays at 03:00 in the n8n instance timezone. It starts a research run through the local AdsRadar API, checks its status every three minutes, and upserts results in Google Sheets by page_id after the run completes successfully and passes its health check. The API server must already be running.

Flow: n8n schedule trigger → Local AdsRadar Python API → Meta Ads + store & review checks → Health check → Google Sheets upsert.

Built as a local MVP; can be deployed to a cloud or VPS n8n instance for 24/7 operation. Its alert message is prepared, with notification channel integration next.

Python · Web scraping · Meta Ads Library API · Self-hosted n8n · Google Sheets

Automation · runs locally · n8n and Supabase · MVP

Shopify Web Scrape

A local n8n workflow that collects Shopify product data and tracks price snapshots in Supabase.

Every six hours, n8n reads the store list from Supabase and processes stores one at a time. For each store, it marks the status as SCRAPING and requests up to 250 products from the public /products.json endpoint.

It records each product's ID, first-variant price, and store domain in product_snapshots, then upserts the product using the store domain and product ID. After processing, it marks the store SUCCESS and updates last_scraped_at.

Flow: Supabase store list → n8n 6-hour schedule → Shopify /products.json → product_snapshots insert → PostgreSQL REST upsert.

Built as a local MVP; can be deployed to a cloud or VPS n8n instance for 24/7 scheduled runs.

Self-hosted n8n · Supabase · PostgreSQL · REST upsert · JavaScript

Continental Autonomous Mobility Philippines, Inc. (Quality - Analysis Center) · Internship project

Analysis Center Booking System

An internal product-test booking application I designed and coded during my full-stack internship, built around what the team's engineers needed.

The system supported product-test bookings and equipment registration. I wrote all of the code: login and sign-up forms, a custom annual booking calendar, an attachment manager that transfers selected files to the department FTP server, and an Equipment Registration interface with add, edit, and delete in Oracle Database.

The stock Visual Studio calendar couldn't be customized enough, so I built the annual calendar on a DataGridView with months as rows and days as columns. It reads each booking's start and end dates from Oracle. Attachments are saved one file at a time to the FTP server and the database to prevent errors.

I began with system design and flowcharts, gathering feedback from engineers, other employees, and the department manager. Before working with Oracle Database, I practiced SQL queries using Microsoft Access. A fellow intern contributed early design ideas, which I refined into the final interface.

We used C# from October through December 2024, then switched to Visual Basic in January 2025 because the team was more familiar with it.

Flow: System design & flowcharts → C# / Visual Basic desktop UI → Custom DataGridView calendar → Oracle Database CRUD → Department FTP file transfer.

C# · Visual Basic · SQL · Oracle Database

KodoGen Security Systems · Flutter · MVP / Prototype

Mobile Inventory System

An offline-first MVP for tracking custody of high-value field equipment across deployment sites.

KodoGen plans to tag issued equipment with QR codes holding each item's serial number. On a daily, weekly, or monthly check-in, field personnel scan the code and take a photo, so the team knows where each item is and who held it last.

For the MVP, I built the core features: QR scanning, photo capture saved to a folder named after the serial number, and local storage of the photo, its file path, and the serial number. It works fully offline. I handled the camera so it shuts down cleanly after each scan, and tested on a physical Android phone and an iPhone using Codemagic cloud builds.

Flow: Scan QR serial → Capture photo → Save photo, file path & serial number locally → Periodic check-ins for location & last-holder tracking.

Flutter · Dart · Codemagic · Offline-first

Thesis · with Zeus Karl Pascual · Best Research

EmoSense

A guidance-support thesis combining webcam-based facial-expression recognition, a PHP/MySQL dashboard, and student assessments.

EmoSense is our thesis: a guidance-support system for school guidance associates. Its integrated webcam feeds an image-processing pipeline built with OpenCV and TensorFlow Lite to analyze facial expressions during a session. A 25-item yes/no assessment covers bullying, family problems, academic stress, and suicidal ideation. The system includes a PHP/MySQL web dashboard for session records and AI-generated recommendations for guidance associates. The thesis frames EmoSense as a support tool, not a replacement for human judgment.

The thesis reports a 4.54/5 overall system-quality rating (Outstanding). This measures system quality, not emotion-recognition accuracy.

I proposed the concept and developed the system code with adviser guidance. My co-researcher, Zeus Karl Pascual, led the written paper.

Flow: Webcam-based image processing → OpenCV + TensorFlow Lite → PHP / MySQL web dashboard → OpenAI API → Raspberry Pi 4B.

Image processing · OpenCV · TensorFlow Lite · PHP / MySQL · OpenAI API · Raspberry Pi 4B

Live website · Live

Amara Celestina Event Website

A custom responsive site for a 2027 milestone event.

A custom website for an upcoming 2027 milestone event. I designed the pages, built the front end, and deployed it to Vercel.

Flow: Page & responsive layout design → Static HTML / CSS front end → Vercel deployment.

amaracelestina.vercel.app

HTML / CSS · Responsive design · Vercel

Personal knowledge system · Personal project

Autonoma

A local-first Markdown vault that organizes project knowledge and gives AI tools relevant context when you choose to share it.

Built with Obsidian, Autonoma organizes project notes, decisions, and reusable AI guidance into a structured personal Second Brain.

Flow: Capture and organize notes → Link related knowledge → Explore connections with Graphify → Share selected context with an AI tool.

AI access is not automatic: compatible local tools need permission, while other AI tools need selected notes uploaded or pasted.

Markdown · Obsidian · Graphify · AI context design

Seminar course project, 2025

RFID Gesture Photobooth

A Python and OpenCV photo booth with MediaPipe gesture detection, RFID activation, and collage output.

For our seminar course, I built a photo booth combining gesture-recognition software with an RFID trigger. Tapping an RFID card activates the booth; a detected peace sign starts the countdown and four-photo capture. OpenCV arranges the photos into a timestamped collage.

Flow: RFID tap → Arduino + MFRC522 → USB serial link → Python → MediaPipe peace-sign detection → 4 photos → OpenCV collage.

The Arduino and Python talk both ways over serial, and each 1920×1080 collage is saved with a timestamp. The booth was presented as part of our seminar requirement, shortly before graduation.

Python · OpenCV · MediaPipe · PySerial · Arduino (C/C++) · MFRC522 RFID

Skills

What I work with

Languages

Python, JavaScript, C#, Visual Basic, Dart, SQL, C/C++ (Arduino)

Web and mobile

Flutter, PHP, HTML/CSS, responsive UI design

Data

SQL Server, Oracle Database, MySQL, PostgreSQL (Supabase), Microsoft Access

Reporting

Excel export, Looker Studio (basic), RDLC reports (basic)

Automation

Self-hosted n8n workflows, web scraping and data pipelines, REST APIs, scheduled jobs, Google Sheets integration

AI and vision

OpenCV, MediaPipe gesture recognition, facial emotion recognition, TensorFlow Lite, LLM APIs, prompt engineering

Tools

Git, GitHub, Visual Studio, VS Code, Codemagic (cloud builds), Linux (Debian on Raspberry Pi), Windows command line, Vercel, Cloudflare Pages

Practice

System architecture and flowcharting, application lifecycle management, adapting to unfamiliar codebases, AI-assisted development

Device integration

PySerial, QR and USB camera integration, Arduino, Raspberry Pi, RFID (MFRC522)

Experience

Where I've worked

Freelance Software Engineer

KodoGen Security Systems · Client since July 2025

I started by providing on-site technical support and service documentation for client deployments. As the work grew, I became the lead technical resource for KodoGen. I built an offline-first Flutter MVP for QR-based equipment custody tracking and modernized the Windows HR system for a security-agency client, migrating its database from MS Access to SQL Server Express and refactoring its VB.NET codebase.

Full-Stack Developer Intern

Continental Autonomous Mobility Philippines, Inc. · Quality - Analysis Center · October 2024 to March 2025

During my internship in the Quality - Analysis Center, I designed and coded the team’s internal product-test booking application from system flowcharts through Oracle Database integration, incorporating feedback from engineers and the department manager and refining early design ideas from a fellow intern. I built login and sign-up forms, a custom annual calendar on a DataGridView that reads booking dates from Oracle, one-by-one file attachment saving to the department FTP server and Oracle Database, and Equipment Registration CRUD. We used C# from October through December 2024, then switched to Visual Basic in January 2025 because the team was more familiar with it.

Certification

TESDA · NC II — Computer Systems Servicing

Issued June 2025 · Valid until June 2030

Read certification details

National Certificate II from the Technical Education and Skills Development Authority, earned through competency assessment. It covers installing and configuring computer systems, setting up computer networks and servers, and maintaining and repairing computer systems and networks.

Contact

Ready to build something?

Tell me what software you need built, what data or tools you already have, and when you need it. I'll get back to you with how I'd approach it.

Email medexterfernandez.dev@gmail.com

GitHub · dekstre ↗LinkedIn ↗Facebook ↗

Dexter Fernandez

SOFTWARE ENGINEER

Calamba, Philippines | dexterfernandez.dev@gmail.com | dexter-fernandez.pages.dev | github.com/dekstre | linkedin.com/in/dekstre

PROFESSIONAL SUMMARY

Software Engineer with a BS in Computer Engineering (2025) experienced in modernizing Windows desktop and database systems, designing and coding internal business applications, and building workflow automations, web applications, and mobile MVPs across .NET (C#, VB.NET), SQL Server, Oracle, Python, Flutter, and self-hosted n8n.

PROFESSIONAL EXPERIENCE

Freelance Software Engineer | KodoGen Security Systems | Jul 2025 – Present

Started with on-site technical support and service documentation for client deployments, then became the lead technical resource.
Modernized a client Windows HR Management System by migrating its database from Microsoft Access to SQL Server Express, refactoring 10,000+ lines of VB.NET data-access code from OleDb to SqlClient, and replacing Access queries with SQL Server views.
Built a two-table performance-appraisal workflow, case-sensitive login, data-grid record views, create/edit/delete activity logs, Excel exports for Looker Studio reporting, and client task-list features for clearances, medical records, commendations, suspensions, and monthly inventory disposition reports.

Full-Stack Developer Intern | Continental Autonomous Mobility Philippines, Inc. - Quality, Analysis Center | Oct 2024 – Mar 2025

Designed and coded the internal Analysis Center Booking System from system flowcharts through Oracle Database integration, incorporating engineer and manager feedback. Built login and sign-up forms, a custom DataGridView annual calendar reading booking dates from Oracle, one-by-one FTP and database attachment saving, and Equipment Registration (add, edit, delete).
Practiced SQL queries in Microsoft Access before Oracle integration; used C# from October through December 2024, then switched to Visual Basic in January 2025, which the team was more familiar with.

TECHNICAL SKILLS

Languages:: Python, JavaScript, C#, Visual Basic, Dart, SQL, C/C++ (Arduino)
Frameworks & web:: .NET, Windows Forms, Flutter, PHP, HTML/CSS, responsive UI design
Automation & data pipelines:: Self-hosted n8n, REST APIs, web scraping, scheduled jobs, Google Sheets integration
Databases & reporting:: SQL Server Express, Oracle Database, MySQL, PostgreSQL (Supabase), Microsoft Access, Excel export, Looker Studio (basic), RDLC reports (basic)
AI, vision & systems:: OpenCV, TensorFlow Lite, MediaPipe, LLM / OpenAI APIs, prompt & AI context engineering, Obsidian / Markdown / Graphify
Tools & device integration:: Git, GitHub, Visual Studio, VS Code, Codemagic, Debian Linux, Vercel, Cloudflare Pages, PySerial, QR & USB camera integration, Raspberry Pi, Arduino, MFRC522 RFID

SELECTED PROJECTS

AdsRadar | Local research automation MVP (Python, Meta Ads Library API, n8n, Google Sheets)

Built a scheduled weekly Python and n8n workflow (Mondays 03:00) that gathers Meta advertisers, checks storefront and review signals, filters and scores brands, polls API status every 3 minutes, and upserts results to Google Sheets by page_id after passing health checks.

Shopify Web Scrape | Product & price-tracking workflow MVP (n8n, Supabase, PostgreSQL, JavaScript)

Built a local n8n workflow running every 6 hours that reads store lists from Supabase, fetches up to 250 products per store via /products.json, records price history in product_snapshots, and upserts product records via REST.

Mobile Inventory System | Offline-first Flutter MVP (Flutter, Dart, Codemagic)

Built an offline-first equipment custody-tracking MVP for KodoGen Security Systems with periodic QR scan and photo check-ins, clean camera lifecycle handling, and local storage of the photo, file path, and serial number; tested on physical Android and iPhone devices via Codemagic cloud builds.

EmoSense | Thesis | Best Research (Python, OpenCV, TensorFlow Lite, PHP/MySQL, OpenAI API, Raspberry Pi 4B)

Proposed the concept and developed the system software for a school guidance-support system combining webcam facial-expression recognition, a 25-item student assessment, a PHP/MySQL dashboard, and AI counseling recommendations; rated 4.54/5 (Outstanding) across 6 ISO/IEC 25010 system-quality dimensions.

EDUCATION AND CERTIFICATION

BS Computer Engineering | Laguna College of Business and Arts | 2025

TESDA NC II, Computer Systems Servicing | Issued June 2025 · Valid until June 2030