Full Stack Developer · Cebu

I build products
that actually matter.

I build production-ready systems end to end, from public web products and mobile apps to tools that make people's work and lives easier.

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Karl Christian Ajero

Experience

Work

Flying Tigers Express

Full Stack Developer

September 2025 – Present

  • Lead development for the Business Portal. Built key features, including bulk shipment import, partner dashboards, and waybill generation workflows.
  • Architected the Business API integration layer — REST endpoints for bookings, batch tracking, webhook registration, rate limiting, and sandbox isolation — enabling programmatic shipment management for enterprise clients.
  • Implemented Business Team Wallet on the backend and customer app: wallet activation, Xendit-backed top-ups, shared balance across team members, and default booking payment method configuration.
  • Built centralized activity logging with entity-scoped metadata (shipments, businesses, invoices, tickets, API keys) and an Admin Ops global activity view with category filters, search, and human-readable formatting.
  • Integrated third-party logistics workflows (e.g. Lalamove, Consegnia) via integration batches and webhook handlers, plus partner-facing webhook management in the Business Portal.

Sanct

Co-Founder & Technical Lead

December 2023 – September 2025

  • Co-founded Sanct, a DTI-registered startup that designs and builds websites and web platforms for clients. Led the technical side, from system architecture to delivery.
  • Built and delivered multiple client websites, including a real estate website and our biggest project, DepEd MPS.
  • Technical lead for DepEd MPS, a Mean Percentage Score monitoring platform for DepEd Region X, owning system architecture and engineering delivery for regional score encoding, section management, and school/division performance review.
  • Defined the technical roadmap and led the engineering team in shipping features aligned with how DepEd divisions and schools work, from educator score entry to division-level oversight and reporting.
  • Architected a scalable system for high-volume education data, now supporting 50,000+ students, 200,000+ encoded scores, and 2,000+ active educators, and expanding to other regions in the Philippines.
  • Set engineering standards around role-based access, encode-time data validation, and division/school aggregation, prioritizing security, data integrity, and maintainability for government use.

Symph

Full Stack Developer Intern

April 2023 – September 2023

  • Contributed to the development of LessonPlanner, an AI-driven platform designed to automate and simplify lesson planning for educators.
  • Built features for SnapProduct, a generative AI tool that transforms standard product photos into professional, photoshoot-ready images.
  • Collaborated within cross-functional teams to develop, maintain, and enhance features across the full stack for various client and internal products.
  • Maintained and optimized multiple ongoing web applications, ensuring code reliability and a smooth user experience across different project environments.

Freelance

Full Stack Developer

2021 – 2022

  • Designed and built websites and small web applications for individual and small-business clients, handling requirements gathering, development, and deployment independently.
  • Delivered a mix of marketing/portfolio websites, web apps with backend and database integration, and e-commerce sites, working directly with clients from scope to launch.
  • Managed the full project lifecycle solo — client communication, UI implementation, backend/API setup, and post-launch fixes — building early experience in end-to-end ownership later applied in production roles.

Selected work

Projects

Web, mobile, and machine learning work built for real users.

WildChats

WildChats

March 2025 - April 2025

WildChats is a real-time chat application built for Cebu Institute of Technology - University (CIT-U) students, also known as Wildcats! This platform enables seamless communication among students, faculty, and organizations, providing a modern and secure chatting experience.

WebsiteSource
AgriVision

AgriVision

March 2025 - March 2025

AgriVision is a mobile application that utilizes deep learning and computer vision to detect lettuce diseases from images.

Source
ShrimpSense

ShrimpSense

January 2025 - February 2025

Monitor, predict, and optimize shrimp farming with data-driven insights and real-time analytics. ShrimpSense ensures optimal water quality, disease prevention, and farm efficiency using AI-powered technology.

WebsiteSource
HealthBook - App

HealthBook - App

October 2024 - December 2024

Welcome to Healthbook — a cutting-edge digital health tracker designed to manage and monitor your complete medical history all in one place! Whether it's vaccination records, prescriptions, or family health details, Healthbook is your go-to app for simplifying your healthcare management.

Website
Lersch Grossman Algorithm Visualizer

Lersch Grossman Algorithm Visualizer

October 2024 - December 2024

A lerch grossman algorithm visualizer built using Java and JavaFX. This aims to provide a visualizer for this specific algorithm using JavaFX for mining Engineers.

Source
TeknoLost

TeknoLost

October 2024 - December 2024

A lost and found mobile application developed as part of my 2nd-year project at CIT-U. Build using Android Studio, Java and Firebase for backend. The app aims to streamline the process of reporting and recovering lost objects.

Source

Research

Personal Back Squat Form Correction System Using Mediapipe Pose Estimation and QLoRa-Fine-Tuned Language Models

May 2026 · 12th International Conference on Education and Training Technologies (ICETT), Seoul, South Korea

Developed an AI-driven system that utilizes computer vision and fine-tuned LLMs to provide real-time feedback and correction for athletic form.

Presented this research at the 12th International Conference on Education and Training Technologies (ICETT) in Seoul, South Korea, in May 2026.

View on IEEE Xplore

Background

Education

  • Cebu Institute of Technology - University

    Bachelor of Science in Computer Science

    2022 – 2026

  • Mater Dei College

    STEM Engineering - Senior High

    2020 – 2022

Toolkit

Skills

Languages

TypeScript · JavaScript · Python · Java · Swift

Web

React · Next.js · Angular · AngularJS · Vue.js · Node.js · Express.js · NestJS · Django · FastAPI

Desktop / Mobile

React Native · Expo · Android Studio · Swift · Flutter

Data

MongoDB · MySQL · PostgreSQL · Supabase · Firebase

Infrastructure

GCP · AWS · Railway · GitHub Actions · CI/CD

Contact

Get in touch

karlchristianajero@gmail.com