Aaron Chou 

Senior Software Engineer (DeFi
Projects) • freelancer  

May 2023 - Present

Contributed part-time to developing decentralized finance (DeFi) applications focusing on
concentrated liquidity and benefits from swap fees and staking rewards, while actively pursuing self-study and research in blockchain / AI technologies.

Key Responsibilities and Achievements:

DCA System Development and Optimization:

• Architected and maintained a robust Dollar Cost Averaging (DCA) system for automated crypto investment strategies.
• Developed a high-availability, fault-tolerant job scheduler using GCP Cloud Scheduler, managing periodic DCA investments for multiple users and strategies.
• Optimized transaction timing and gas costs through blockchain monitoring integration, achieving a 15% reduction in average user transaction fees.

Backend Infrastructure and API Development:

• Collaborated closely with Solidity developers to integrate smart contract functionality with backend services.
• Conducted thorough analyses of Solidity codebases to ensure robust interaction between backend systems and on-chain logic.
• Implemented real-time blockchain event listeners and transaction management systems for up-to-the-minute data updates.

Performance and Security Enhancements:

• Optimized subgraph schemas and mappings to efficiently support multiple DeFi protocols and user-specific data requirements.
• Contributed to Solidity smart contract code reviews, focusing on backend integration and potential security vulnerabilities.
• Implemented comprehensive error handling and monitoring systems, ensuring high availability
  and reliability of DeFi services.

Technologies and Skills:

• Programming Languages: Node.js, TypeScript, Golang, Solidity.
• Blockchain Interaction: Web3.js, Ethers.js.
• The Graph: GraphQL, subgraph development.
• Cloud Services: AWS, Google Cloud.
• Database: MySQL/CloudSQL, Redis / Memorystore.
• Version Control: Github API Development: RESTful APIs, GraphQL
• DevOps: Github Action for CI /CD.

Continuous Learning and Research:

• Dedicated 10+ hours weekly to self-study in advanced blockchain concepts and emerging DeFi
  protocols.
• Researched and experimented the security issues on the Ethereum network.
• MEV flashbot POC focus on uniswap v2 / pancake swap.
• Use LLM framework like langchain to create chatbot application with RAG technique.
• Create a Go backend service that monitors Uniswap V2 WETH/USDC liquidity pool swap events in real-time via Ethereum JSON-RPC, calculating user rewards and delivering instant notifications through WebSocket for a trading campaign system. 
• Create Flash Coupon Delivery API side project using Golang to achieve high performance of API.

Senior Cryptocurrency and Blockchain Developer  •  Coolbitx

Mar 2020 - Mar 2023

Specialized in developing and managing API endpoint services for leading cryptocurrencies, including Bitcoin, Ethereum, Polkadot, and Cosmos. Proficient in building robust, scalable cryptocurrency infrastructure and services.

Key Achievements and Responsibilities

API Development and Infrastructure:

• Architected and deployed a high-performance crypto API platform using Terraform Infrastructure as Code (IaC), ensuring scalability and maintainability.
• Engineered a comprehensive Cryptocurrency API leveraging GCP Cloud Run and Apollo GraphQL, featuring:
  • Advanced cold and hot wallet management systems
  • Efficient staking and transaction data retrieval mechanisms
  • Precise gas cost estimation across diverse blockchain networks
• Implemented multi-chain support by containerizing and self-hosting blockchain nodes (Bitcoin, Litecoin, Ethereum, Cardano, Polkadot ... etc.) using Golang gin framework, enhancing system flexibility and performance.

Performance Optimization and Security:

• Conducted rigorous load testing and performance evaluations of crypto APIs using k6, ensuring optimal performance under various conditions.
• Developed secure wallet crypto authentication APIs utilizing AWS Lambda and CloudHSM, facilitating safe cold wallet firmware upgrades.
• Optimized and integrated the Golang-based Subscan Explorer for efficient substrate-based chain analysis, improving data accessibility and insights.

Innovative Solutions and Integrations:

• Spearheaded the development of cryptocurrency cash-out services for European markets, utilizing Nest.js, PostgreSQL, and Typeform to create a seamless user experience.
• Contributed to integrate Coolbitx LaunchPad API with EVM-based smart contracts, expanding platform capabilities.
• Engineered near-real-time contract data monitoring services for OLAP preprocessing and analysis, enabling rapid decision-making and insights.
• Designed and implemented LaunchPad contract event data collectors using Kubernetes cronjobs and GCP Pub/Sub, enhancing data collection and processing efficiency.

Leadership and Operational Excellence:

• Managed critical on-call duties, demonstrating quick problem-solving skills and ensuring minimal service disruptions.
• Spearheaded issue-resolution meetings with business teams, effectively bridging technical and business perspectives.
• Maintained comprehensive documentation, facilitating knowledge transfer and system understanding across the organization.

Technical Proficiencies:

• Blockchain Technologies: Bitcoin, Ethereum, Polkadot, Cosmos, Cardano, Litecoin, Solana, Tezos, Avax
• Cloud Platforms: Google Cloud Platform (GCP), Amazon Web Services (AWS)
• Programming Languages: Golang, JavaScript/TypeScript
• Frameworks & Tools: Apollo GraphQL, Nest.js, Terraform, Kubernetes, Docker
• Databases: PostgreSQL
• Testing & Monitoring: k6, CloudHSM
• Infrastructure: Cloud Run, Lambda, Pub/Sub, Kubernetes

Full Stack Engineer / Cloud
Infrastructure Architect  •  ElandFintech

Feb 2019 - Mar 2020

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

Blockchain Development:

• Developed a Layer 1 private-chain solution based on Ethereum's Geth project, similar to Omni Layer on Bitcoin.
• Implemented a custom blockchain explorer comparable to Etherscan for the private chain.
• Designed and implemented a Stellar anchor service system for managing fiat/crypto in a payment solution
• Conducted a proof-of-concept (POC) exploring PrivateKey Vault solutions, experimenting with Shamir's Secret Sharing techniques and AWS Key Management Service (KMS) integration

High-Performance Transaction Processing:

• Engineered a high-speed transaction channel for the Stellar blockchain using AWS Lambda and SQS.
• Implemented a transaction envelope mechanism to optimize throughput and ensure transaction integrity.

 Cloud Infrastructure and DevOps:

• Designed and implemented comprehensive AWS infrastructure monitoring, logging, and alert systems
• Integrated payment gateways (e.g., Stripe) into the Stellar anchor transfer service
• Implemented Infrastructure as Code using AWS CloudFormation for continuous deployment pipelines
• Utilized Elastic Stack (ELK) for creating detailed infrastructure monitoring dashboards

Security and Quality Assurance:

• Integrated static code analysis using SonarQube in GitLab CI pipeline
• Implemented comprehensive unit testing and integration testing frameworks using Mocha
• Ensured code quality and security through automated testing and continuous integration practices

Leadership and Agile Methodologies:

• Served as a technical lead, guiding team members through daily Scrum processes.
• Conducted weekly review sessions to ensure project alignment and progress.
• Fostered a culture of continuous improvement and knowledge sharing within the team.

Key Technologies:

AWS (Lambda, SQS, KMS, CloudFormation), Ethereum, Stellar, GitLab CI, SonarQube, Mocha, ELK Stack, Stripe API

Full Stack Engineer  •  Bincentive

Jul 2018 - Feb 2019

Developed comprehensive trading products and cryptocurrency solutions, leveraging a wide range of technologies across the full stack.

Key Projects and Achievements:

Trading Gateway Backend:

• Engineered a robust Restful API for Trading Gateway using Node.js, Swagger, and PostgreSQL
• Implemented the backend based on the ccxt open-source project, enhancing functionality and performance
• Designed and executed comprehensive integration tests to ensure system reliability and accuracy

Trading Platform Frontend:

• Developed a responsive and intuitive Trading Platform frontend using Vue.js
• Implemented real-time data updates and interactive charts for enhanced user experience
• Optimized performance for handling high-frequency trading data

Marketing and User Engagement:

• Created engaging Marketing Event Landing Pages using Vue.js integrated with WordPress
• Implemented user behavior data collection by integrating amplitude.js
• Analyzed user interactions to drive product improvements and marketing strategies

Blockchain and Cryptocurrency:

• Conducted in-depth studies on Solidity Smart Contracts for Ethereum blockchain
• Researched and implemented CryptoCurrency Wallet connect protocol solutions
• Explored Hashicorp Vault for secure secret management in cryptocurrency applications

Technical Skills:

Frontend

• Vue.js
• HTML5, CSS3, JavaScript
• Responsive Web Design
• User Behavior Analytics (amplitude.js)

Backend

• Node.js
• RESTful API Design
• Swagger for API Documentation
• PostgreSQL
• Integration Testing

Blockchain & Cryptocurrency

• Solidity 
• WalletConnect protocol 
• ccxt Trading Library

DevOps & Security

• GitHub Flow
• Hashicorp Vault
• Secret Management

Methodologies

• Full Stack Development
• Agile Development Practices

Full Stack Engineer  •  Wistron ITS

Mar 2017 - Jul 2018

Contributed to development efforts across diverse projects, including internal company systems, BPO management, banking applications, enterprise search solutions, and e-learning platforms.

Key Projects and Achievements:

BPO Recruiting Management System:

• Designed and implemented a comprehensive Business Process Outsourcing (BPO) project recruiting management system
• Developed both front-end and back-end components using Node.js, Vue.js, and MySQL
• Streamlined recruiting processes, improving efficiency and candidate management

Banking Credit Card Application System:

• Architected and developed a microservice-based system for digitizing banking credit card applications
• Utilized Docker Swarm for containerization and orchestration, ensuring scalability and easy deployment
• Implemented services using Golang and Python Flask, with Vue.js for the front-end
• Designed a robust data architecture using CouchBase and MySQL for efficient data management and retrieval
• Significantly reduced application processing time and improved overall system reliability

Enterprise Dialog Search Engine:

• Developed an advanced dialog search engine application for Cisco Jabber IM system
• Leveraged the ELK (Elasticsearch, Logstash, Kibana) stack for powerful full-text search capabilities
• Created a responsive front-end interface using Vue.js for seamless user interaction
• Implemented backend services in Golang, ensuring high performance and concurrency
• Enhanced communication efficiency within the organization by providing quick access to relevant conversations

E-Learning Platform:

• Designed and developed the front-end of an e-learning website using Vue.js
• Created an intuitive and engaging user interface to enhance the learning experience
• Implemented responsive design principles for cross-device compatibility

Corporate Website Maintenance:

• Maintained and updated the company's official website
• Ensured content relevance, visual appeal, and optimal performance
• Implemented SEO best practices to improve online visibility

Technical Expertise

Programming Languages

• Golang
• JavaScript/TypeScript
• Python
• Node.js

Front-end Technologies

• Vue.js
• HTML5, CSS3
• Responsive Web Design

Back-end & Databases

• MySQL
• CouchBase
• Flask (Python)

DevOps & Cloud

• Docker Swarm
• Microservices Architecture

Search & Analytics

• ELK Stack (Elasticsearch, Logstash, Kibana)

Methodologies

• Full Stack Development
• System Architecture Design
• Agile Development Practices

Full Stack Developer  •  freelancer

Mar 2016 - Mar 2017

Pursued professional growth through freelance projects and self-directed learning in IoT, Big Data, and Blockchain technologies. Key accomplishments include:

Mobile and Web Development:

• Engineered an Android social app focused on movie trends, enhancing user engagement in the entertainment space
• Architected a high-availability backend infrastructure using MongoDB, Redis, and Elastic Search, deployed on AWS ElasticBeanstalk

DevOps and CI/CD:

• Implemented a robust CI/CD pipeline using Jenkins and Ansible, integrated with AWS ElasticBeanstalk for streamlined daily development processes
• Orchestrated the migration of backend infrastructure to a microservices architecture using Docker, improving scalability and maintainability

Cloud and Serverless Computing:

• Optimized backend costs by refactoring infrastructure to a serverless architecture using AWS Lambda
• Designed and deployed a live-streaming infrastructure utilizing Wowza Streaming Engine, complemented by the development of an Android streaming app

Continuous Learning and Skill Enhancement:

• Mastered Big Data technologies including Hadoop, Spark, Flink, as well as advanced topics in Natural Language Processing and Machine Learning
• Developed proficiency in IoT systems and blockchain technology through intensive self-study and project-based learning

Professional Development:

• Actively participated in technology-focused social groups and conferences, with emphasis on IoT, Machine Learning, and Fintech
• Stayed abreast of industry trends through regular engagement with technology publications like DIGITIMES

Web Developer   •  EcrowdMedia

Mar 2014 - Feb 2016

Led the development of cutting-edge e-book solutions for one of Taiwan's largest e-book companies (Readmoo ECrowdMedia), focusing on enhanced user experience and content security.

Key Projects and Achievements

Advanced EPUB Reader Development:

• Spearheaded the development of a sophisticated EPUB reader by forking and significantly enhancing the Readium open-source project
• Implemented custom features to improve reading experience and compatibility with various EPUB formats
• Optimized performance for smooth page rendering and navigation across different devices

Secure Desktop Application:

• Engineered a robust desktop application using NW.js (Node-Webkit) for cross-platform compatibility
• Implemented a state-of-the-art encryption system combining AES and RSA algorithms to ensure stringent EPUB content protection
• Balanced user experience with robust DRM (Digital Rights Management) to satisfy both readers and publishers

Chrome Extension for Social Reading:

• Designed and developed a Chrome extension to enhance the social aspect of digital reading
• Implemented features for readers to write and share book reviews directly from the extension
• Created a book-sharing mechanism to boost user engagement and community interaction

E-Commerce and Marketing Support:

• Developed dynamic EC (E-Commerce) campaign pages to drive book sales and user engagement
• Ensured responsive design for optimal viewing across various devices
• Collaborated with marketing teams to implement tracking and analytics for campaign performance

Team Leadership:

• maintain and evolve the Reader project.
• Championed Agile methodologies, significantly accelerating project delivery timelines and substantially enhancing team productivity.

Technical Expertise

E-book Technologies

• EPUB format
• Readium open-source project
• Digital Rights Management (DRM)

Programming Languages & Frameworks

• JavaScript/TypeScript
• NW.js (Node-Webkit)
• Chrome Extension APIs

Security

• AES encryption
• RSA encryption
• Secure content delivery

Web Technologies

• HTML5, CSS3
• Responsive Web Design
• E-commerce platform integration

Development Practices

• Open-source project forking and customization
• Agile project management
• Version control (e.g., Git)

Leadership

• Team management
• Mentoring and skill development
• Project planning and execution

Software Engineer •  shuttle

Jul 2012 - Feb 2014

evelopment and optimization of Android systems for tablet devices, focusing on customization, performance enhancement, and seamless updates across diverse hardware configurations.

Key Projects and Achievements:

Android Tablet BSP and Framework Development:

• Spearheaded the development of Board Support Packages (BSP) for various Android tablet models
• Customized and extended the Android framework to support unique hardware features and OEM requirements
• Optimized boot processes and system performance for enhanced user experience
• Implemented power management optimizations to extend battery life on tablet devices

Android Source Tree Optimization:

• Engineered a flexible Android source tree structure to efficiently support multiple customer-specific variants
• Developed a modular approach to customize Android builds for different hardware configurations and feature sets
• Implemented build system optimizations to reduce compilation time and resource usage
• Created a streamlined process for integrating OEM-specific applications and services

OTA Update Infrastructure:

• Designed and developed an Over-The-Air (OTA) update server infrastructure using Node.js
• Implemented secure and efficient mechanisms for delivering and applying system updates
• Created a robust rollback system to ensure device stability in case of update failures
• Developed an admin dashboard for managing and monitoring the OTA update process across device fleets

Multi-Device Support Mechanism:

• Architectured a flexible system to support various Android devices with minimal code changes
• Implemented a hardware abstraction layer to standardize interactions between the Android framework and diverse hardware components
• Developed a dynamic configuration system to auto-detect and adapt to different hardware capabilities
• Created comprehensive documentation and guidelines for adding support for new devices

3G Dongle Integration:

• Successfully ported and integrated 3G dongle support for Android tablets
• Developed and optimized drivers for various 3G dongle models to ensure broad compatibility
• Implemented power-efficient connection management for improved battery life
• Created a user-friendly interface for 3G network configuration and management

Technical Expertise:

Android Development

• Android Framework customization
• Board Support Package (BSP) development
• AOSP (Android Open Source Project) modifications
• OTA update systems

System Programming

• Linux kernel customization
• Driver development
• Power management optimization
• Boot process optimization

Programming Languages

• Java
• C/C++
• Node.js

Networking

• 3G/4G integration
• Wireless protocols
• Network driver development

Development Tools & Practices

• Android Studio
• Git version control

Hardware Integration

• SoC (System on Chip) integration
• Peripheral device support
• Hardware abstraction layer development