Chun-Cheng Lee

Chun-Cheng
Lee.

Backend-focused software engineer. APIs, AI integrations, and payment systems you can click into and verify.

Los Angeles, CA

View projectsGet in touch

Open to backend and full-stack roles

What I build.

Backend & APIs

Django, FastAPI, and Node services with clean REST design, JWT auth, and PostgreSQL behind every endpoint.

Django, FastAPI, PostgreSQL, REST

AI Integration

GPT-4o Vision apps, RAG chatbots with multi-turn memory, and LLM-augmented workflows shipped to production.

GPT-4o, RAG, LangChain, Claude API

Payments & QA

Stripe subscription billing, webhook event processing, and end-to-end test automation that keeps releases safe.

Stripe, Webhooks, CI/CD, Test Automation

 

Public projects

 

Live demos

3

Languages spoken

Skills.

Languages
Python, JavaScript, TypeScript, SQL, Java, Kotlin
Backend & APIs
Django, Django REST Framework, FastAPI, Flask, Node.js, Express.js, REST API Design, Webhook Handling, JWT Authentication, Google OAuth
Frontend
React, HTML/CSS, Bootstrap, Chrome Extension APIs (MV3)
AI / LLM Integration
Claude API (streaming, tool use), OpenAI GPT-4o and Vision, RAG pipelines, Chroma vector store, MCP servers, SSE streaming, Prompt engineering
Databases & Caching
PostgreSQL, MySQL, MongoDB, Redis, Database Design, Query Optimization
DevOps & Cloud
GitHub Actions (CI/CD), Heroku, Linux, Git, Docker
Payments
Stripe API, Subscription Billing, Invoice Automation, Webhook Event Processing
Testing & QA
Unit Testing, Integration Testing, Test Automation, Test Case Design, Jira, Defect Tracking
AI Dev Tools
Claude Code, Cursor (AI-assisted IDE), GitHub Copilot, LLM-augmented development
Practices
Agile/Scrum, Code Review, API Security, Technical Documentation, Cross-Functional Collaboration
Currently Learning
AWS (EC2, S3, RDS), System Design

Real work.

Pulled live from GitHub.

All repositories

Resume.

Backend Engineering

Python (Django, FastAPI), PostgreSQL, REST APIs, Docker, and GitHub Actions CI/CD.

AI Integration

GPT-4o Vision multimodal apps, prompt engineering, OpenAI API, LangChain workflows.

AI Chatbot

Full-stack AI chatbot with GPT-4o-mini, RAG via ChromaDB, multi-turn memory, JWT auth, follow-up suggestions, and a resizable widget.

Payments & Quality

Stripe payment systems, end-to-end QA automation, test-driven development mindset.

Open resume

Contact.