Joseph Karl Crisostomo

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

Summary

Technology-agnostic full-stack engineer who ships end-to-end across whatever stack a project needs — Rails, Django, or React on AWS. Comfortable picking up unfamiliar tasks fast and delivering in short, demo-driven loops.

Skills

• Full-Stack: Ruby on Rails, Hotwire (Turbo/Stimulus), Python, Django, React, TypeScript, JavaScript, HTML, CSS
• Backend & Data: Node-style REST integrations, PostgreSQL, RDS, Redis (Elasticache), Amazon MQ
• Infra & DevOps: AWS (EC2, S3, EKS, CloudFormation, CodeBuild, ECR, CloudWatch), Docker, Kamal, CI/CD
• Quality: Automated testing (unit/controller), Grafana K6 load testing, Git

Experience

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

On-site · Feb 2024 – March 2026

• Built and managed containerized (Docker) services across on-premise Ubuntu servers and AWS, orchestrated with Elastic Kubernetes Service (EKS).
• Stood up an automated build pipeline: S3 for source, CodeBuild for builds, ECR for images — plus repeatable infra provisioning via AWS CloudFormation.
• Drove unit-test coverage from 0 to ~90%, improving system maintainability and integrity.
• Integrated core AWS data services: RDS (database), Elasticache/Redis (caching), Amazon MQ (message broker).
• Optimized database queries through in-depth inspection and root-cause analysis; ran automated smoke and load testing with Grafana K6.

Web Developer (Intern) — Dashlabs.ai

Remote · Aug – Sept 2022

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

Education

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

2019 – 2023