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Chia Kang Jin
Full Stack Developer
Tokyo, Japan | xiankai@gmail.com
github.com/xiankai | linkedin.com/in/chia-kang-jin-7719b555/
Summary
Senior Full-Stack Engineer with 13+ years of experience building and scaling web applications across Japan and Singapore. Currently at Autify (test automation SaaS), where I maintain infrastructure serving 300+ companies, drive BI/data analytics initiatives, and build AI tooling including MCP servers and AI-powered automation agents. Broad stack depth: TypeScript/React frontends, Ruby on Rails / Node.js backends, AWS infrastructure, and a growing focus on AI/ML integration.
Experience
Senior Full-Stack Engineer
Autify, Inc. — Tokyo, Japan | April 2022 – Present
- Drove data analytics initiatives across the organization's Business Intelligence stack (cost tracking, data governance, incident reporting)
- Created an ETL pipeline (AWS Glue / Python) that processed 20M+ unstructured log records in days instead of weeks for AI self-healing analysis
- Created AI tooling for existing products (MCP servers, automated dependency updates with Devin AI Agent)
- Maintained the test automation pipeline for web / mobile automation, serving 300+ companies
- Architected solutions for email delivery and PDF generation
- Debugged native Selenium WebDriver and Chromium internals to stabilize browser automation
- Active development on Chrome extensions for recording and replaying browser actions
- Reduced mobile device wait time by ~50% by pre-warming devices before test execution
- Assisted in building the test automation pipeline for a desktop application; drove development of the scheduling feature
- Deployed a self-serve infrastructure provisioning API (Pulumi) with AWS IAM permission isolation
- Prototyped a natural language AI Agent for mobile test automation (prompt adherence, element location, model selection)
Tech stack: TypeScript, React, Redux, Apollo GraphQL, Electron, Chrome Extension API, Appium, Ruby on Rails, GraphQL, Postgres, SQLite, Github Actions, CircleCI, Jest, Testing Library, Mock Service Worker, RSpec, Playwright, AWS (ECS/EKS), Kubernetes, Pulumi, Terraform, Holistics, Athena, Redshift, Airbyte
Full Stack Developer
Rakuten, Inc. — Tokyo, Japan | Oct 2019 – March 2022
- Coordinated between 4 departments (20+ people) to build an in-house analytics platform with Form Builder, Query Builder, and multi-timezone support
- Helped maintain CI/CD pipeline and supported transition to Kubernetes
- Took ownership of the logging architecture
- Mentored developers and drove productive code reviews
- Improved QA process with automated testing
- Migrated the codebase to TypeScript
- Developed an ESLint plugin for GraphQL linting
Tech stack: React, Redux, MaterialUI, TypeScript, Tailwind, Node.js, GraphQL, hapi.js, MongoDB, Redis, RabbitMQ, Presto, Druid, Elasticsearch, Python 3, Jupyter Notebook, Jest, Cypress, Testrail, Jenkins, Docker, CloudFoundry, Kubernetes, JIRA, Confluence, Bitbucket
Senior Software Engineer
Tectus Dreamlab — Singapore | Apr 2018 – Aug 2019
- Solely maintained a web app for Proceq (non-destructive testing tools) — chart visualizations with Highcharts, geo-analytics with Google Maps, offline HTML reports with jsdom
- Collaborated on the Screening Eagle platform (construction industry management tool): dynamic form builder, PDF rendering with PSPDFKit, 3D rendering with three.js
- Spearheaded integrated testing that brought bugs down to near-zero
- Integrated i18n and implemented a one-click deployment pipeline
Tech stack: React, Redux, redux-saga, ant.design, Storybook, Webpack 4, Flow, Jest, Cypress, Sentry, Gitlab CI, Jenkins, Docker, AWS
Frontend Developer
Spacebib — Singapore | Feb 2015 – Mar 2018
- Built public-facing and internal admin site for a sporting events platform
- Seamless API integration with backend, continuous UX iteration
- Monitored integration tests and dashboard metrics for site uptime
Tech stack: React, Redux, MobX, Apollo, Bootstrap, SASS, JSPM, Webpack 2, TypeScript, Mocha, Selenium WebDriver, Webdriver.io, Browserstack, CakePHP, GraphQL, Jenkins
Full Stack Developer
Pytheas Travel — Singapore | Jul 2012 – Apr 2014
- Built a whitelabel CMS SaaS catering to 50+ travel agents
- Migrated 35K customers, 1K products and 5 clients, preserving DNS and email functionality
- Automated deployment of dev/production servers with Puppet
- Built a proof-of-concept logging framework with Elasticsearch
Tech stack: Codeigniter 2, jQuery, PHPUnit, Selenium Grid, Nginx, Jenkins, AWS, Puppet, CentOS6
Web Developer
Doorstep Luxury — Singapore | Mar 2012 – Jun 2012
- Developed a WordPress e-commerce site for luxury goods
- Built a standalone web-based POS system (webcam scan + receipt printing)
Web Developer
KLIF Media — Singapore | Dec 2011 – Feb 2012
- Built a prototype social media site on Symfony 2
Education
Bachelor of Arts (Psychology)
National University of Singapore | Aug 2008 – Jun 2011
Electives in Programming and Linguistics
Skills
Primary: TypeScript, React, Redux, Node.js, Ruby on Rails, GraphQL, PostgreSQL, AWS, Kubernetes, Docker
Also familiar with: R, Angular, Elm, Rust, Go, React Native/Expo, Python/pandas, Vue 3, C#, C++
AI/ML: MCP servers, Playwright automation, AWS Glue, Athena/Redshift, Huggingface, Devin AI
AI-assisted development: Claude Code, part of my everyday engineering workflow
Languages: English (Proficient), Chinese (Basic), Japanese (Basic)
Certifications
- Red Hat Certified System Administrator (RHCSA) — ID: 140-241-662
- Algorithmic Toolbox — University of California, San Diego / HSE on Coursera
- Huggingface Audio Course Certificate of Excellence (xiankai123)
Meetup Talks
- Alternative Libraries for React — JSPM and MobX — ReactJS Singapore
- Data-driven development with Flow — React Singapore
Personal Projects
Pre-AI: built without AI coding agents.
- Remote Explorer Pre-AI · being revived with AI coding agents — Android file explorer over Samba (Kotlin / Jetpack Compose)
- Doorbell Detector Pre-AI — ML audio classification to detect doorbell sounds (Python)
- FFXIVFurigana Pre-AI — C# plugin to display furigana over Japanese in FFXIV chat
- ChatHistory w/ Vector DB Pre-AI — Import old chat history with semantic search via vector DB
- Triple Triad V2 Pre-AI — Rust experiment replicating FFXIV card game logic
- XIVAnalysis Pre-AI — Collaborative combat performance analyzer for FFXIV (React, SemanticUI)
- Pokémon Go Map Pre-AI — Local map tracking EX-raid predictions, serving 3K+ users (TypeScript, MobX, Leaflet, d3.js, Mapbox/OSM)
- Triple Triad Pre-AI — Multiplayer FFXIV mini-game via WebRTC (peerjs, redux-observables/RxJS)
- Web Crawler Pre-AI — Disney Store crawler notifying 15 subscribers of new stock (cURL, Redis, Mailchimp)
- Discord Bot Pre-AI — Web crawler over 10K+ pages with job queue (phantomjs, Redis, Node.js)
- Server Administration Pre-AI — Managed VPS for bots/websites; migrated 6 times across Linode/AWS/Digital Ocean with Puppet/rsync/mysqldump at 100% uptime