Chino Hills, CA — Open to full-time roles

Aaron Chai

Full-Stack Developer

Full-stack developer who ships commerce systems

Download resumeSee the work

About

Systems that sell

I build and run the commerce systems behind two live cosmetics storefronts — a loyalty program, a serverless API gateway, data pipelines, and a 40-section Shopify design system spanning 2,600+ SKUs.

I work across the stack in React, TypeScript, Node.js, and Python, and I put LLM and agentic tooling (Claude, MCP) into production, not just demos. Currently pursuing an MSCS at Georgia Tech, expected 2027.

+50%

online sales lift in 6 months

2,600+

SKUs across two storefronts

75%

p95 latency cut (800ms to <200ms)

+40%

email repeat-purchase rate

Experience

Where I've shipped

  1. Sep 2024 – Present · Ontario, CA

    Beauty 21 Cosmetics Inc. · L.A. Girl / L.A. Colors

    Full Stack Developer

    • Architect and maintain the PRO Points loyalty program end-to-end (React/TypeScript, Node.js/Express, PostgreSQL) across two storefronts — 637 products, 2,600+ SKUs, 10,000+ customers per brand — with idempotent earn/redeem transaction handling, delivering a +50% online sales lift in the six months post-launch.
    • Design and deploy a Node.js/TypeScript serverless API gateway (Vercel, JWT/CORS, Joi validation, rate limiting, circuit breaker, retry with backoff, Redis TTL caching, Prometheus), reducing Stamped.io API error rate 40% and cutting p95 latency from 800ms to under 200ms.
    • Ship a Shopify OS 2.0 design system of 40+ modular Liquid/Tailwind/Web Component sections across two storefronts, migrating an 80-template codebase into the component library and cutting code duplication 60% and deploy-cycle time 45%.
    + 7 more
    • Apply WCAG 2.1 AA contrast and keyboard-navigation standards across all 40+ storefront sections, resolving 120+ accessibility violations with zero compliance-related escalations across both brands since launch.
    • Engineer a Python/pandas PIM pipeline normalizing 10,000+ product attributes across two source systems with header-diff comparison and idempotent upserts, surfaced in a Next.js review dashboard — eliminating 8 hrs/week of manual data entry (a 60% reduction).
    • Deploy and maintain six automated customer lifecycle flows (Shopify Flow plus async webhook consumers) integrating Klaviyo, Bazaarvoice, and Stamped.io via the GraphQL Admin API, processing 1,200+ monthly event triggers with dead-letter handling and sustaining a +40% email repeat-purchase rate lift.
    • Automate the daily Bazaarvoice-to-PowerReviews product-feed pipeline via GitHub Actions CI/CD with exponential-backoff retry, Jest TDD, and Slack failure alerting — cutting catalog sync lag from 24 hrs to under 1 hr and failure-detection lag from 4 hrs to under 5 minutes.
    • Improve Core Web Vitals (LCP) on the L.A. Girl storefront 35% by diagnosing render-blocking third-party JS race conditions and implementing script-defer strategies, validated against Lighthouse scoring.
    • Build a reusable React component library and GraphQL data-fetching layer for the Locksmith-gated B2B distributor portal — infinite-scroll catalog browsing, metaobject-driven product display, and a quote-request wishlist across 120+ distributor accounts.
    • Establish a branch-per-environment GitHub-to-Shopify CI/CD pipeline with PR preview environments and automated linting, cutting deploys from a multi-hour manual process to under 20 minutes and enabling same-day hotfixes across both storefronts.

  2. Mar 2024 – Jun 2024 · Pomona, CA

    Calhome (T-Motor Sports Inc)

    Web Developer (Project-Based)

    • Built a Python multi-channel catalog sync pipeline integrating 5 retailer APIs (Amazon SP-API, Wayfair, Home Depot, Walmart, Lowe's), normalizing product schemas and automating async submissions — driving 35% cross-platform sales growth within the 3-month engagement.
    • Achieved 99.5% inventory accuracy across 500+ SKUs and 5 sales channels with automated Python validation and reconciliation scripts, cutting discrepancy resolution from ~2 days to same-day and manual data entry 60%.
    • Designed a SKU attribute normalization schema mapping 500+ product attributes across 5 retailer APIs, establishing a single-source-of-truth catalog and cutting ~5 hrs/week of per-channel manual data reformatting.
    + 1 more
    • Redesigned the Shopify storefront with responsive layouts, optimized imagery, and cross-device navigation, reducing page-load time 28% and enabling unified catalog display across all 5 marketplaces.

Selected work

Built and measured

AI in production

AI-assisted engineering, shipped

I work across the stack in React, TypeScript, Node.js, and Python, and I put LLM and agentic tooling (Claude, MCP) into production, not just demos.

LLM & GenAI integration

Claude API integration with prompt engineering and grounded generation — responses constrained to real source data instead of model guesses. The resume chat on this page runs the same way.

Agentic tooling

Claude Code and MCP automation inside the daily production workflow — agents act on real systems through typed tool interfaces, and humans handle the exceptions.

Paperclip B21

Internal multi-agent AI system automating e-commerce operations

An internal multi-agent AI automation system — 11 specialized agents built on Claude and MCP — that automates e-commerce operations across Shopify, ClickUp, Gmail, and Google Drive. It routes daily store maintenance, reporting, and content tasks that previously required hands-on work.

Claude · MCP · Shopify · ClickUp · Gmail · Google Drive

Read the case study — Paperclip B21

Ask my resume anything —

Toolbox

What I work with

Languages

  • JavaScript (ES6+)
  • TypeScript
  • Python
  • SQL (PostgreSQL, MySQL)
  • HTML5
  • CSS3
  • Java (coursework)

Frontend

  • React
  • Next.js
  • TailwindCSS
  • Liquid
  • Web Components
  • WCAG / Accessibility

Backend

  • Node.js
  • Express
  • Spring Boot (cert)
  • REST APIs
  • GraphQL
  • JWT / CORS
  • Webhooks
  • Microservices
  • Distributed systems

Cloud & DevOps

  • AWS Lambda
  • Vercel Serverless
  • Docker
  • CI/CD (GitHub Actions)
  • Prometheus
  • Observability
  • Cloud-native

Databases & Testing

  • PostgreSQL
  • MySQL
  • SQL/NoSQL data modeling
  • Jest
  • TDD
  • Code review
  • Agile/Scrum

AI & Tools

  • Claude Code
  • GitHub Copilot
  • LLM/GenAI API integration
  • Agentic / MCP automation
  • Prompt engineering
  • Git/GitHub

Education

Credentials

Georgia Institute of Technology

M.S. in Computer Science · Atlanta, GA

Expected 2027

San Diego State University

B.S. in Computer Science · Dean's Honors List (GPA 3.5+)

Dec 2023

Certifications

  • Frontend Developer Career Path · Scrimba2025
  • Spring by Google (Microservices) · Coursera2025
  • IBM Full-Stack Developer · Coursera2024

Need the one-pager?

Download resume

PDF — updated Jul 2026

Contact

Let's talk

Hiring, or just curious? My inbox is open.