Han Pan

- Developed a NFT Marketplace supporting multiple digital wallets. Enabled NFT listings and purchases. - Created a Dynamic NFT Project updating NFT metadata based on city temperatures using off-chain Oracles. - Built DApp Tweet, a decentralized app with Metamask wallet integration, user management, and dynamic NFT generation. - Worked on Learnweb 3 Bounties, implementing OAuth2 logins and user NFT digital identity restoration. - Developed a DAO Voting System based on the Compound protocol, covering proposal creation to execution. - Engineered a Borrowing & Lending Contract for ETH to WETH collateralization and DAI coin borrowing. - Created an Ethereum Wallet with functionalities like mnemonic phrase generation and transfers. - Source codes: https://github.com/phanke - Technologies: Solidity, ERC20, ERC721, Ethers.js, Hardhat, Chainlink, Moralis, Wagmi, IPFS, Fleek,React, Vue, Next.js, Java, Node.js, Openzeppelin library, Chainlink library

- Developed Satellite management system using Java as a part of team and independently. - Integrated the Nacos component as a central configuration service to reduce costs by 50% on projects operation and maintenance. - Replaced the client-server polling mechanism with the WebSocket long connection mechanism, ensuring real-time data interaction and reducing the server's concurrent pressure. - Introduced multi-data source management tool - Mybatis-Plus to enhance adaptation to multiple data sources and project's delivery capability. - Stored satellite alarm data using time-series database OpenTSDB and improved the interaction performance between front-end and back-end system by 800% in terms of retrieving alarm information with its Restful API for chart. - Improved system primes efficiency for handling fault and warning tasks through referring most similar cases and solutions to operating primes using Elasticsearch's scoring mechanism. - Refactored inefficient code and slow SQL to decrease CPU resource usage and accelerate project performance. - Technologies: Spring Cloud ,MySQL , Kafka , MyBatis , Nacos , Redis , MySQL, Elasticsearch , Docker

- Developed an IOT project - Digital Factory using Java in a team of 12 members. - Built a microservice gateway using Spring Cloud Gateway to manage all requests, ensuring the security of accessing other microservices and implemented idempotence processing for Post requests and black/white list controls based on Redis. - Authenticated users through JWT tools and implemented JWT renewal operations based on Redis. - Integrated Nacos as the microservice configuration center to reduce maintenance costs and managed the overall health status of the microservices as a service registry. - Implemented RabbitMQ message middleware for pushing asynchronous alert information and subscribed to the queue in Topic mode, allowing for different push methods such as SMS, email, WeCom. - Completed the load balance for the entire microservice chain through Spring Cloud OpenFeign and Ribbon. - Employed the AT mode of the Seata component to guarantee the atomicity and consistency of transactions across different services. - Established a Quartz job scheduling service and expanded it to a highly available cluster architecture. - Technologies: Spring Cloud , Mybatis, Nacos , RabbitMQ , Seata , Redis , MySQL , Docker , Kubernetes

- Developed IM-Plus and Portal Website projects using Java and JS based on distributed architecture. - Integrated Netty as framework for IM-Plus project, promoted single server to supports 1 million long connections. - Enhanced the service's read and write performance using Redis as a server cache. - Developed a feature using RabbitMQ's dead-letter queue as a delay queue to close unpaid orders. - Consolidated Zookeeper as the service registration center and implemented a polling load balancing strategy. - Achieved complex page presentation logic with jQuery.js. - Used Zookeeper's ephemeral sequential nodes for implementing distributed locks to prevented the overselling phenomenon of goods during the rush purchase. 8.Increased the speed of retrieving millions of chat records by 500% by replacing MySQL to Elasticsearch. - Technologies: Spring Boot , Hibernate ,Redis , MySQL , Oracle , Vue.js , jQuery.js , Netty, Apache ZooKeeper , Elasticsearch

- Developed applications using a tech stack that included Struts2, Springboot, and Hibernate. - Utilized BootStrap and jQuery for front-end page rendering. - Employed Velocity template technology to generate static email templates. - Integrated MongoDB as the project's file server. -Technologies: SpringMVC , Spring , Maven , BootStrap , Easyui.js , Hibernate , Oracle