Senior BackEnd Engineer,

        Coolbitx, Mar 2020 - now

As a seasoned professional in the cryptocurrency space, I've played a pivotal role in developing and managing API endpoint services for leading cryptocurrencies such as Bitcoin, Ethereum, Polkadot, Cosmos, and more. My key responsibilities include:

• Designing and deploying a robust crypto API platform using Terraform Infrastructure as Code (IaC).
  
• Developing a Cryptocurrency API relying on GCP Cloud Run exposed by Cloud Endpoints, utilizing Apollo GraphQL for cold and hot wallet management. The API facilitates staking and transaction data retrieval or estimate gas cost across various blockchain networks, including Ethereum, Solana, Ripple, Tezos, Polkadot, and more.
  
• Containerized self-host blockchain node into a pod serving by Golang gin framework for multi-chain routing support. Self-host blockchain nodes include Bitcoin, Litecoin, Ethereum, Cardano, and Polkadot.
• Use k6 to do load test for crypto API capacity and performance evaluation
• Developed containerized cryptocurrency cash-out services facilitating seamless conversion of cryptocurrencies to fiat currencies in the European region, utilizing Nest.js, PostgreSQL, and Typeform.
  
• Implementing wallet crypto authentication APIs using AWS Lambda and CloudHSM for enhanced security of cold wallet firmware upgrade service. 
• Integrating and optimizing Subscan Explorer from open source project for substrate-based chain exploration and analysis. The project is written in Golang.
• Collaborating on integrating Coolbitx LaunchPad API with EVM-based smart contracts, ensuring compatibility and functionality.
  
• Developing near real-time contract data monitoring services for OLAP preprocessing, enabling timely insights and analysis. 
• Establishing LaunchPad contract event data collectors using Kubernetes cronjobs and GCP Pub/Sub for efficient event monitoring and data analysis.
  
• Periodic on-call scheduling, serving as the first line of response for real-time or initiating meetings with business teams to resolve issues, and maintaining comprehensive process documentation.
  

Full Stack Engineer / Cloud Infrastructure Architect

ElandFintech, Feb 2019 - Mar 2020

Responsible for development blockchain layer1 and layer2 application of STO token exchange solution

• Implement Omni Layer like layer 1 private-chain solution base on ethereum blockchain Geth project. 

• Implement Etherscan like blockchain explorer 

• Design stellar anchor service system which is used for managing fiat/crypto in a payment solution. 

• Design PrivateKey Vault solution using Shamir's Secret Sharing like technique with AWS KMS. 

• AWS Serverless application for layer 2 high-speed transaction channels in the stellar blockchain. 

• AWS infrastructure monitoring 、logging、alert system design and implementation. 

• Integrate Payment Gateway like Stripe into stellar anchor transfer service. 

• Static code scan using SonarQube in gitlab ci pipeline also include unit testing and integration test by mocha. 

•  Use Infrastructure as Code by CloudFormation for CD pipeline
• DR planning per half year 
  

 As a tech lead, I am also responsible for leading the team members to run the daily scrum process and weekly review.

      Full Stack Engineer

Bincentive , Jul 2018 - Feb 2019

Responsible for development trading products by GitHub Flow

• Backend Restful API for Trading Gateway (using Node.js, Swagger, PostgreSQL) which. based on ccxt open source project  also include integration test.

• Trading Platform FrontEnd development (using Vue.js)

• Marketing Event Landing Page (using Vue.js with WordPress) 

• Solidity Smart Contract (Ethereum) and CryptoCurrency Wallet connect protocol solution study.
  

• Hashicorp Vault secret management study.

• User behavior data collection by integrating with amplitude.js.

Full Stack Engineer

Wistron ITS,  Mar 2017 - 2018 Jul

Responsible for development inner requirement of the company and BPO (Business Process Outsourcing) project 

• recruiting management system design (front-end and back-end using Node.js, Vue.js, MySQL) 

• micro service system development and architecture design for digitizing of banking credit card application (using Docker Swarm, Golang, Vue.js, Python Flask, CouchBase, MySQL) 

• Dialog search engine application development for Cisco Jabber IM system (using ELK, Golang and Vue.js) 

• e-learning website front-end design (using Vue.js) 

• official website maintain

Full Stack Developer 

 freelance, Mar 2016 - Mar 2017 

Responsible for freelance jobs and self-learning (IoT, BigData, Blockchain) by developing my side projects. 

• Developed an Android social app about movie trends. 

• Build app backend infra using MongoDB, Redis, ElaticSearch with high availability by AWS ELB, ASG. 
• Build Jenkins CI server and Ansible / ElasticBeanstalk CD function for the daily development process. 
• Using Docker to refactor back-end infra into MicroService architecture. 
• Using AWS Lambda to minimize the cost of Back-End Infra to a serverless architecture. 
• Setup live-streaming infra by Wowza Streaming Engine and develop an Android streaming App. 
• self-learning BigData technique including Hadoop, Spark, Flink, NLP, machine learning. 
• Join social groups and conferences which focus on IOT, MachineLearning, Fintech and read technology newspaper to realize trends of technology and marketing. 

Web Developer 

ecrowdMedia, Feb 2014 - Mar 2016

 Responsible for developing epub reader for one of the largest epub company in Taiwan (readmoo ecrowdmedia)

• Develop epub Reader which is forked from Readium open-source project. 
• Develop desktop app using nw.js with aes + rsa encryption for epub content protection.  Chrome extension for books review from readers and sharing books.
• EC campaign page design. Leading two team members to maintain Reader project.   

Software Engineer

  shuttle, Jul 2012 - Feb 2014

Responsible for developing Android Tablet projects.

• Develop BSP (Board Support Package) and Android framework for Android Tablet.

• Develop OTA server infra for android device upgrade automation by node.js 

• Optimize Android source tree to support different kinds of customers.

• Create mechanisms for Android to support various devices

• Porting 3G Dongle for Android Tablet.

Embedded Software Engineer 

                Inventec, Sep 2008 - Jul 2012 

Responsible for developing Embedded System and Android 

• Porting Linux driver in ARM / TI / Freescale platform for ebook product like Nook for Barnes Noble. 

• Develop driver to control audio codec and camera behavior.

• Organize Business Process Outsourcing project.

• Developing Web UI on VoIP phone.