JunJun Mobad

Cheng JunKai

works

All
FullStack
Blockchain
AI
Bot & Automation

Online hotdog bar
Ordering system
Crew
Matching system
Tatto NFT
OneDex
CryptoNitro
Sketch Tool
Hayami NFT
Vodeo Meeting platform
Telegram bot
Trading bot
Multi-Language Chatbot
Sports Club LP
Free Image generator
Uni-Fy
SupDucks
Logarithm
PureChain Capital
DotBet
Greubel Forsey
Logarithm Games
Crypto Telegram Casino Bot
Telegram mini game

resume

2023.12 - present

Full Stack Blockchain Developer

Self employed 2023.12 - present

Designed and deployed an NFT marketplace supporting ERC-721/1155 with MetaMask/WalletConnect auth, batch minting (EIP-2309), and royalty enforcement (EIP-2981), processing 5K+ transactions monthly.

Built Several SAAS platforms using Makerkit-The Leading SAAS starter kit, saved the development time by 50%.

Participated in Vuetify community and built Vuetify-custom ChatGPT using RAG technology with Vuetify founder.

Optimized DeFi contracts (AMMs, staking pools) using Foundry, achieving 30% lower gas costs vs industry benchmarks.

Architected and implemented cross-chain interoperability solutions across 5+ major networks (Ethereum, Polygon, BSC, Solana, Avalanche) using LayerZero and Wormhole, enabling seamless asset transfers andcontract calls.

Performed 50+ comprehensive smart contract audits using OpenZeppelin Defender and Foundry's Fuzzing,identifying 12 critical vulnerabilities across DeFi protocols and NFT collections.

Developed a diverse range of Telegram and Discord bots, including Votebot, Sniper bot, ControllerBot, Alert bot, and Dropmail bot, leveraging Python and Golang to implement customized functionalities and enhance user engagement across platforms.

Architected responsive dApp with Wagmi hooks (useAccount, useContractRead) and dynamic transaction simulations (Tenderly), cutting user onboarding time from 50s → 12s.

Pioneered 15+ Solana solutions with Anchor + @solana/web3.js, reducing CPI errors by 40% and failed TXs by 35% through custom guards/fee markets while accelerating development 30% with RPC simulations.

Built cross-chain DEX smart contracts with Python-based automation (web3.py), integrating KyberSwap Elastic's concentrated liquidity and WOOFi's asymmetric price curves to reduce slippage by 40% for large swaps.

Engineered high-performance blockchain interactions using ethers.js v6 and Web3.js, implementing EIP-1193 provider standardization to reduce wallet connection errors by 65%.

2024.3 - 2024.9

Technical Lead

IMMENSITY STUDIOS, remote 2024.3 - 2024.9

Provided technical guidance and support to team members, fostering a collaborative and productive work environment.

Led the development of a user-friendly, mobile-responsive company website, overseeing the architecture and implementation using Next.js, Prisma, and MongoDB.

Successfully managed remote collaboration, ensuring effective communication and project delivery.

2020.5 - 2023.12

FullStack Blockchain Engineer

varomatic, HongKong 2020.5 - 2023.12

Developed a cutting-edge web applications using Angular, React, Laravel enhancing user experience and boosting engagement by 40% through intuitive design and seamlessfeatures.

Architected RESTful APIs and microservices using Express.js, NestJS, Django, Flask and GraphQL for scalable backend solutions.

Deployed 12+ secure presale smart contracts on Ethereum/BSC/Solana, implementing fixed-swap, Dutch auction, and vesting mechanisms using Solidity/Rust.

Integrated seamless cross-chain wallet connectivity (MetaMask, Coinbase Wallet, Rainbow) via Wagmi + RainbowKit, reducing onboarding time by 40% and supporting 5+ EVM networks (Ethereum, Polygon, BSC) with real-time balance/transaction fetching using Ethers.js.

Integrated infrastructure using AWS Lambda, S3, and DynamoDB, reducing operational costs by 20%.

Worked in CI/CD environment (Jira pipelined with slack, Jenkins – automatic testing system, Dock deployment).

2017.8 - 2020.2

FrontEnd Developer

WestRoadSouth Limited, HongKong 2017.8 - 2020.2

Developed responsive web applications using Angular, React.js,Vue and Redux, improving UI/UX efficiency.

Maintained advanced proficiency in React state management strategies, leveraging Flux architecture, Redux, Context API, and Hooks resulting in a 30% reduction in application load times.

Engineered RESTful API integrations using Axios and Fetch with request caching and concurrent call optimization, achieving 30% faster response times through chunked transfers and smart retry logic.

Utilized Cypress and Cucumber frameworks for robust end-to-end testing.

quote

Love what you do and do what you love. Don't listen to anyone else who tells you not to do it. You do what you want, what you love. Imagination should be the center of your life.

Ray Bradbury

author

about me

Hello! I am JunJun.

I help startups, enterprises, and individuals turn their ideas into reality using my knowledge and experience in web and blockchain development.

I am a premium member of makerkit community, also member of Vuetify community and contributor.

my services

Frontend
Modern frontend development supporting user friendly, mobile friendly.
Backend
Building backend system supporting large scalability, high performance, robust security.
BlockChain
Blockchain development on Ethereum, Solana supporting Web3 integration, Smart contracts, dApps
Artificial Intelligence
Machine learning, natural language processing, computer vision, and other AI techniques.

my skills

Front end

Html

Css

Javascript

JQuery

TypeScript

React

Vue

Nuxt

Angular

Svelte

React Native

Flutter

Tailwind CSS

Ant Design

MUI

Nextui

Back end

Node.js

Express

Python

Django

GoLang

Nest

Laravel

Fast API

Ruby on Rails

Databse

MySql

PostgreSql

Firebase

Supabase

Mongodb

Tools & services

GraphQL

Googlemap

Mail Service

Payments

Googletag

Browser Extension

Shopify

AWS

AZure

Linux

Docker

CI / CD

Jira

Github

BlockChain & Web3

Bitcoin

Ethereum

Solana

Polkadot

Binance

Cardano

Solidity

Rust

Web3

Walletconnect

Substrate

Trading view/bot

AI Development

LLM

Chatbot

OpenAI/ChatGPT

TTS / STT

Image Generation

LangChain

Tensorflow

Pytorch

feedbacks

I had the pleasure of working with him on a project that required expertise in React and Node, and I must say, I was thoroughly impressed with his technical abilities and professionalism. He is a full stack developer who has a deep understanding of both front-end and back-end development, and is able to seamlessly integrate the two to deliver exceptional solutions.

Ekim Kaya

Internet personality

He gave this job everything it needed and more! Our company was able to meet its goals one month ahead of schedule thanks to the research he put together. We would contract him for freelance work again.

Narjes

Project Manager

It has been a great Experience working with him. He has a great knowledge and it is pretty organize to execute tasks in rapid way and understands the needs of the business offering his technical view in each use case. Happy to work with him again.

Store owner

Exabytes

He demonstrated deep knowledge of React, TypeScript, and the entire frontend ecosystem. Their ability to quickly understand project requirements, troubleshoot issues and implement solutions was outstanding. He not only delivered high-quality code, but also continually introduced creative ideas that enhanced the user interface and user experience.

Wassim Azirar

CTO & Founder

activity

Coding
Find a job you enjoy doing, and you will never have to work even a day.
Economics
Economics is probably my favorite field besides coding.
Art
Art fuels my creativity.I enjoy drawing pictures in my spare times.
Tennis
I love the intense in powerful serves, precise shots, and strategic rallies.

quote

Your love for what you do and willingness to push yourself where others aren't prepared to go is what will make you great.

C. Ronaldo

Football player

get in touch

Linkedin
Let`s connect. see my skills and experience in Linkedin.
Whatsapp
Message to +63 9931350391. I love chatting with co-workers.
Telegram
Message to @junwithu. I am always open to co-work, communication.
Github
My GitHub username is barneylogo. Let`s collaborate.

Mail me

Works

Resume

About

Activity

Contact

resume

2023.12 - present

Full Stack Blockchain Developer

Self employed 2023.12 - present

Designed and deployed an NFT marketplace supporting ERC-721/1155 with MetaMask/WalletConnect auth, batch minting (EIP-2309), and royalty enforcement (EIP-2981), processing 5K+ transactions monthly.

Built Several SAAS platforms using Makerkit-The Leading SAAS starter kit, saved the development time by 50%.

Participated in Vuetify community and built Vuetify-custom ChatGPT using RAG technology with Vuetify founder.

Optimized DeFi contracts (AMMs, staking pools) using Foundry, achieving 30% lower gas costs vs industry benchmarks.

Performed 50+ comprehensive smart contract audits using OpenZeppelin Defender and Foundry's Fuzzing,identifying 12 critical vulnerabilities across DeFi protocols and NFT collections.

Architected responsive dApp with Wagmi hooks (useAccount, useContractRead) and dynamic transaction simulations (Tenderly), cutting user onboarding time from 50s → 12s.

Engineered high-performance blockchain interactions using ethers.js v6 and Web3.js, implementing EIP-1193 provider standardization to reduce wallet connection errors by 65%.

2024.3 - 2024.9

Technical Lead

IMMENSITY STUDIOS, remote 2024.3 - 2024.9

Provided technical guidance and support to team members, fostering a collaborative and productive work environment.

Led the development of a user-friendly, mobile-responsive company website, overseeing the architecture and implementation using Next.js, Prisma, and MongoDB.

Successfully managed remote collaboration, ensuring effective communication and project delivery.

2020.5 - 2023.12

FullStack Blockchain Engineer

varomatic, HongKong 2020.5 - 2023.12

Developed a cutting-edge web applications using Angular, React, Laravel enhancing user experience and boosting engagement by 40% through intuitive design and seamlessfeatures.

Architected RESTful APIs and microservices using Express.js, NestJS, Django, Flask and GraphQL for scalable backend solutions.

Deployed 12+ secure presale smart contracts on Ethereum/BSC/Solana, implementing fixed-swap, Dutch auction, and vesting mechanisms using Solidity/Rust.

Integrated infrastructure using AWS Lambda, S3, and DynamoDB, reducing operational costs by 20%.

Worked in CI/CD environment (Jira pipelined with slack, Jenkins – automatic testing system, Dock deployment).

2017.8 - 2020.2

FrontEnd Developer

WestRoadSouth Limited, HongKong 2017.8 - 2020.2

Developed responsive web applications using Angular, React.js,Vue and Redux, improving UI/UX efficiency.

Maintained advanced proficiency in React state management strategies, leveraging Flux architecture, Redux, Context API, and Hooks resulting in a 30% reduction in application load times.

Engineered RESTful API integrations using Axios and Fetch with request caching and concurrent call optimization, achieving 30% faster response times through chunked transfers and smart retry logic.

Utilized Cypress and Cucumber frameworks for robust end-to-end testing.

quote

Love what you do and do what you love. Don't listen to anyone else who tells you not to do it. You do what you want, what you love. Imagination should be the center of your life.

Ray Bradbury

author

Cheng JunKai

Love what you do and do what you love. Don't listen to anyone else who tells you not to do it. You do what you want, what you love. Imagination should be the center of your life.

Ray Bradbury

Frontend

Backend

BlockChain

Artificial Intelligence

Ekim Kaya

He gave this job everything it needed and more! Our company was able to meet its goals one month ahead of schedule thanks to the research he put together. We would contract him for freelance work again.

Narjes

It has been a great Experience working with him. He has a great knowledge and it is pretty organize to execute tasks in rapid way and understands the needs of the business offering his technical view in each use case. Happy to work with him again.

Store owner

Wassim Azirar

Coding

Economics

Art

Tennis

Your love for what you do and willingness to push yourself where others aren't prepared to go is what will make you great.

C. Ronaldo

Linkedin

Whatsapp

Telegram

Github

Love what you do and do what you love. Don't listen to anyone else who tells you not to do it. You do what you want, what you love. Imagination should be the center of your life.

Ray Bradbury