I am an Ethereum and full-stack developer from Singapore. I work on multidisciplinary projects, including:

  • Smart contracts and dApps
  • Full-stack development
  • Privacy and cybersecurity research
  • Tools which enable access to public information

You can reach me at contact@kohweijie.com. My given name (Wei Jie) follows my surname (Koh) as per Eastern name order.

Please encrypt sensitive messages. My GPG key can be found on keyservers such as this. My GPG key signature is:

55B4 84D5 C359 852C 4EBF AB40 90DB 4361 7CCC 1632



An Ethereum mixer built with Semaphore, a zero-knowlege privacy gadget.

Zero-knowledge Mastermind

I built a proof-of-concept implementation of the Mastermind board game which uses zk-SNARKs instead of a trusted third party to enforce game rules.

Stack: Ethereum, Solidity, circom, Typescript, Python, Django


I made a smart contract and dApp to auction off 40 hours of unpaid smart contract development work and find my next job.

Stack: Ethereum, Solidity, web3, Preact, JavaScript, LESS

Source code


An Ethereum dApp that creates time-locked Lunar New Year red packets.

Featured by Business Insider: A Singapore team has come up with the ‘world’s first blockchain-based’ hongbao – and it could change Chinese New Year

Stack: Ethereum, Solidity, web3, Preact, JavaScript, LESS

Source code


A Raspberry Pi Zero image for secure and user-friendly Monero cold wallet generation.

Stack: Raspbian Linux, QEMU, guestfs, Python 3, Bash

Source code


A user-friendly way for lawyers in Singapore to improve their skillsets. I built this as an independent contractor for the Singapore Academy of Law.

Stack: AWS, Nginx, Scrapy, Django, Preact, JavaScript, LESS

Live app

Cybersecurity research and disclosure

I found and reported a security vulnerability in a Wireless@SG system which, if exploited, could have led to widespread SMS spamming at the expense of a major telco in Singapore.



A search engine for Singapore's parliamentary records.

Stack: Elasticsearch, Heroku, Django, Python, ReactJS

Live app

Political quizzes


An online quiz that matches users to political parties contesting in the 2015 Singapore General Election. Received 181,000 users in seven days.

Featured by:

Yahoo News: Find Out Which Party You're Actually Supporting This GE2015
The Online Citizen: Online political literacy tool Electionaire goes viral
The Middle Ground: Nine questions with the Electionaire team

Remain vs Leave

A policy quiz for Britons voting in the Brexit referendum.


A policy quiz for voters in the 2016 West Bengal State Elections.

Stack: Heroku, Flask, Python, JavaScript, CSS, HTML


In 2017, I graduated with a major in cultural anthropology from Yale-NUS College. My undergraduate thesis was The Syncretic Imagination of a New Religious Movement in Singapore, an anthropological study based on ethnographic and historical research.

In 2010, I graduated from Ngee Ann Polytechnic with a diploma in information technology.