Joseph Karl Crisostomo

joseph.dev.ph@gmail.com · +63 960 4431 908 · Manila, PH (UTC+8) · Portfolio Site

Summary

Full-stack engineer who builds visually appealing, mobile-friendly websites and ships them fast — clean responsive design, search-friendly markup, and a prototype-first process so the brand’s message lands.

Skills

• Frontend: HTML, CSS, JavaScript, TypeScript, React, Next.js, responsive/mobile-first UI, design systems
• Backend: Ruby on Rails, Node.js, Python, Django, REST integrations
• Tooling & Infra: Git, AWS, Docker, Kamal, Playwright, Claude Code, Claude Design

Experience

Backend Developer — Department of Science and Technology – Advanced Science and Technology Institute

On-site · Feb 2024 – March 2026

• Built and shipped web services end to end, from development through deployment, in an iterative, feedback-driven process.
• Managed containerized (Docker) services deployed on-premise (Ubuntu) and on AWS.
• Initiated unit testing from 0 to ~90% coverage, improving maintainability and reliability.
• Conducted database query optimization through in-depth inspection and root cause analysis.

Web Developer (Intern) — Dashlabs.ai

Remote · Aug – Sept 2022

• Contributed to the maintenance of the platform’s Patient Management Service.
• Handled customer queries across multiple channels (email, chat).

Selected Projects

Kuryente Watch — live community web app (PWA)

• Designed and built a mobile-first public site with an interactive Leaflet map and clean, scannable layout, now live with real users: https://infanta.kuryentewatch.app
• Server-rendered Rails 8 + Hotwire + Tailwind CSS for fast load and search-friendly markup; deployed via Docker/Kamal.

Aqualytix — production monitoring platform

• Authored a custom responsive design system (single-family type, ~1000-line stylesheet) with a mobile tab-bar navigation, applied consistently across every page: https://aqualytix.hackwithsef.xyz
• Full-stack Ruby on Rails build, deployed to AWS with zero-downtime Kamal deploys.

Education

B.S. in Computer Science — Polytechnic University of the Philippines

2019 – 2023