While working at Cherri Tech, I focused on TapPay, a Payment Gateway solution. It offers multiple payment options and provides a seamless payment experience. In 2021, the product processed transactions exceeding 50 billion NTD. Here are some of the responsibilities and tasks I undertook in this role: • Developed Payment Gateway services using Spring Boot • Wrote test cases with JUnit, Mockito, and PowerMock to ensure code quality • Conducted code reviews with colleagues to maintain software quality standards • Troubleshot and resolved field issues faced by customers

• Utilized KeystoneJS 5, Draft.js, Node.js, React.js, PostgreSQL, and GraphQL to develop customized functions in a newly upgraded CMS • Developed Python schedulers • Maintained READr service using Go and Gin • Achieved optimization of the search engine for a media website by refactoring Python data feed and using an Elasticsearch cluster • Managed CI/CD for all services using Kubernetes, Helm, Flux CD, Drone CI, and Docker • Managed GCP and Nginx configuration

Cathay United Bank (5 months): • Utilized Spring Boot to develop APIs BEANGO CO., LTD. (1 months): • Developed a RESTful API using Java, Play Framework, Apache Kafka, and Hazelcast • Set up infrastructure for the test environment, including Kafka Cluster, MongoDB Replica Set, MySQL, and Mcrouter

• Participated in the development of various web-based B2B SaaS applications, such as Online Fitness Course Booking, POS Management, and Payment Gateway Reporting/Dashboard • Maintained a central authentication service (CAS) based on OAuth2.0 • Followed Clean Architecture principles to develop clean, readable, open-to-extend, close-to-modify, and testable modules • Worked in agile methodology during the software development life cycle (SDLC) process • Involved in data modeling and schema design, ensuring at least 3NF • Achieved optimization of API performance by using Java concurrency classes, tuning SQL statements, and refactoring • Actively participated in tracking and resolving product issues • Wrote test cases using JUnit • Technologies used include Java 8, Play framework, EC2, RDS, SES, Memcached, S3, Intellij IDEA, git, MySQL, MongoDB, Firebase, Swagger, Docker, Jenkins, JUnit, EBean, JPA, and Flyway

Data Management Platform: • Collaborated with the data team to design and develop RESTful serverless APIs for a real-time statistics/visualization dashboard • Utilized Node.js, Serverless Framework, AWS Lambda, AWS API Gateway, AWS RDS, and MySQL • Continuously optimized API performance with SQL tunings and Async module, resulting in an average response time reduction of at least 40% • Designed and implemented an early workflow for clickstream data collection of websites using GTM, JavaScript, and PHP Other Works: • Developed a shopping-cart application using Swift and Storyboard • Modified a slot machine game made with Cocos2d • Created simple and robust tracking SDKs in Objective-C and Swift as a proof-of-concept • Provided technical support for tracking SDKs to advertising clients • Developed web services using PHP, Laravel, and MongoDB Other Specialties: • Biweekly study subjects included ML algorithms, Kaggle competitions, SQL tuning, French, etc.

• Developed native iOS applications compatible with iOS 7.* using Objective-C and Storyboard. Familiar with Auto Resizing, Cocoa Touch, UIKit, GCD, and Instruments (Leaks and Allocations) • Integrated the applications with C-based filesystem and UDP/IP socket networking to perform efficient and reliable remote file access (RFA) • Improved the functionalities of a third-party C-based filesystem • Designed and implemented RESTful APIs using Java Servlet • Published two apps: WiFi@SDCF and WIFI-ShareDisk