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Chia-Ning Kuo (etrex)

Line API Expert | Developer of Kamigo the Chatbot
Senior Web Engineer @New Taipei City, Taiwan


Eslite Spectrum Senior Principal Engineer
2022/01 -
YOCTOL, Inc - Senior Software Engineer
2019/09 - 2022/01
5xRuby, Inc - Senior Web Engineer
2017/10 - 2019/08
SOHO - Chatbot developer
2017/03 - 2017/10
School of Continuing Education, Chinese Culture University - Mobile Application Team Leader
2015/07 - 2017/03
School of Continuing Education, Chinese Culture University - Senior Software Engineer
2014/07 - 2015/07
School of Continuing Education, Chinese Culture University - Software Engineer
2013/03 - 2014/07
School of Continuing Education, Chinese Culture University - Front-End Developer
2011/03 - 2013/03
Tornado Technologies Co., Ltd. - Front-End Developer
2010/09 - 2011/03


National Taiwan University of Science and Technology - Master of Information Management
National Taiwan University of Science and Technology - Bachelor of Information Management


Chatbot design for beginners.
A lecture in NTUST - 2018/05/18
How to take chatbot cases.
Education Training in Sugarfun - 2018/02/26


Free chatbot development e-book

Put some free textbooks related to chatbots made by me. When the textbooks are updated, they will be regularly posted on my fan page. Please subscribe me.


Anyone can make a Kamigo: Build your own LINE chatbot from zero.

Chia-Ning Kuo /DrMaster Press Co., Ltd./352 pages / ISBN:9864342932

This is an introductory book that provides a self-study program for readers who don't have any knowledge in the field of information: "Building a Kamigo of their own." Beginning with the basic concepts of chatting robots, this book gradually teaches all relevant knowledge and realizes a chatbot of its own from scratch! Contains development environment settings, website setup, HTTP protocol, Webhook, Line Messaging API, etc. will be described in detail.

Purchase at Tenlong Computer Book Co, Ltd.

An Automatic Hair Matting System

Chia-Ning Kuo, "An Automatic Hair Matting System." Master's thesis, Department of Information Management, National Taiwan University of Science and Technology, 2011.

Using our automatic hair removal system, as long as the face image is entered, the system will automatically leave the hair behind the picture and quickly generate a hair style database.


Ruby study notes

I collected the problems often encountered and the corresponding solutions to ensure that next time anyone who encountered the same problem can resolve them quickly.



Front end

  • JavaScript / jQuery / HotWire
  • ActionScript 3 / Flash
  • CSS / Bootstrap
  • Chrome Extension

Back end

  • Ruby / Rails
  • C# / ASP.NET MVC
  • Node.js


  • PostgreSQL
  • MySQL
  • Redis

API Experience

  • Line Messaging API
  • Line Login API
  • Telegram Bot API
  • Slack API
  • Facebook Login
  • Facebook Messenger API
  • Facebook Account Kit
  • Trello API

Domain Knowledge

  • Chatbot
  • E-commerce
  • Image Processing
  • Game Design
  • Education
  • Memory Method
  • Artificial Intelligence

Development Process

  • System Analysis / System Design
  • Design Pattern / Refactoring
  • Static Test / Dynamic Test
  • CI / CD
  • Git Command / SourceTree
  • Gitlab / Bitbucket
  • Deploy on GCP / Heroku

Personal Works


It is the most well-known Line chatbot with 600,000 users. It provides services such as chat, fortune telling, weather check, with more features in development.

Line chatbot

MVC chatbot framework based on Rails with Flex Message and LIFF support.

open source

It is an accessory package of Kamigo to support LIFF API.

open source

Kamflex provides a good DSL, allowing you to write LINE Flex Messages using highly flexible and maintainable syntax.

open source
Kamiflex Simulator

An online WYSIWYG editor that allows you to edit Kamiflex syntax and see the results instantly.

open source

A technology demonstration LINE Bot that provides group buying services.

Dice, Don't Thanks

A LINE Bot that provides dice throwing services.

Agricola Score Calculator

A LINE Bot that provides score calculations for Agricola board games.


A LINE Bot that provides all kinds of information that developers need to debug.

Leader of Lunch on LINE

The Leader of Lunch is the meeting host responsible for presiding over what to eat for lunch on LINE and Telegram.

Leader of Lunch on Telegram

The Leader of Lunch is the meeting host responsible for presiding over what to eat for lunch on LINE and Telegram.

Telegram Bot
K-Means Clustering Game

I llustrated the process of k-means clustering with delicate animation by using Flash ActionScript 2.

Flash Game
ETREX's Maze

This maze is characterized by turning the maze instead of turning the character when turning, simulating the reality of the lost plot.

Flash Game
Color test

Verify that if you have absolute color perception or not: as long as you see the color, you can know the corresponding RGB value.

Flash Game

Test whether you have the absolute mouse sensation: the ability to know where the cursor is without looking at the cursor.

Flash Game
Pixel Ah

A game that trains memory and can also be used to measure memory size and upload/download speed in the brain.

Flash Game
Blindfold Sliding Puzzle

A memory game that helps to inprove memory, training the working memory by moving the slider continuously.

Web Game
network editor

Operates the graphs used in graph theory to accelerate the learning efficiency of related theories.

Flash Tool
Fractal generator

A WYSIWYG fractal editor that uses affine transformation to observe fractals.

Flash Tool
Collatz Conjecture

Visualization of the 3n+1 question, see if you can see what is going on.

Flash Animation
Nerd Translator

A short film of the nerd translation machine imitating the TV shopping channel, it is actually a materialized introduction of myself.

Flash Animation
Fractal tree

Using fractals to generate a random 2D tree animation, you can adjust many parameters to change the result.

Flash Animation
Lightning Effect

An attempt to make the lightning effect, click on the mouse and you will see the effect.

Flash Effect
CSS Rubik's Cube

An attempt to make the rubik's cube, you can rotate it by mouse or keyboard.

CSS JS Animation