Yusuke Kohatsu

Ichigo, Inc Oct 2024 - Present

• Contributed to launching a new shipment method using Ruby, TypeScript, and AWS to sell snack boxes.
• Resolved pricing discrepancies from external services such as Shopify and Amazon without overloading the OMS using Ruby, Shopify, external APIs, and Workers.
• Optimised the use of an external API to print shipping labels by implementing bulk batch processing in Ruby.
• Implemented a new listing page to handle urgent tasks due to customs policy updates using TypeScript, Ruby, MySQL, and AWS.
• Removed unused code from complex shipping logic without causing financial damages and adjusted all shipping-related test code using Ruby.
• Handled support request tickets daily for other teams in addition to main tasks.

Skills: Ruby, TypeScript, GraphQL, Sentry, MongoDB, AWS, MySQL, Docker, Shopify, Sidekiq

Sippy Software, Inc Dec 2022 - Aug 2024

• Optimized SQL query to make the call detail record report three times faster.
• Provided a custom shell script for translating call numbers to meet urgent customer needs, bolstering sales by $300 within a week.
• Developed and deployed a new invoice table feature using Python and PostgreSQL.
• Led the design and implementation of highly maintainable and loosely coupled code for distributed components using Python, Go, PHP, and XML-RPC.
• Created robust XML-APIs and ensured their stability with 100% test coverage using Python and pytest.
• Streamlined the development process by configuring build checks and implementing automated unit testing in Go for 10 repositories using the Bitbucket pipeline.

Skills: Python, Go, PHP, PostgreSQL, MySQL, XML-RPC, Jenkins, Apache Thrift, Bitbucket, pytest

DPCode Inc. Jun 2022 - Oct 2022

• Developed and deployed a serverless function using Cloud Functions, Gmail API, TypeScript, and Node.js to seamlessly send customers' invoice PDFs via email.
• Implemented notification logic to remind users of sending invoices using Swift.
• Elevated code maintainability and quality by implementing automation testing and linting using CircleCI for the invoice application.
• Collaboratively designed the system architecture alongside team members, ensuring efficient communication and a well-structured approach to the project.

Skills: Swift, TypeScript, Node.js, Cloud Functions, CircleCI, Firebase

Myadcenter Jan 2022 - June 2022

• Developed a user-friendly form component for purchasing phone numbers with robust validations using Redux, MaterialUI, JavaScript, Next.js, and Twilio API.
• Optimised code efficiency by resolving existing issues and streamlining the retrieval of billing data from the database in Node.js, JavaScript, Express.js, and MySQL.
• Revamped the method for searching and filtering data in Node.js, Express.js, JavaScript, Next.js, and MySQL, enhancing code reusability and scalability.

Skills: JavaScript, Node.js, Express.js, MySQL, Next.js

Hitachi Systems, Ltd Apr 2020 - Sept 2021

• Developed a robust REST API for the user management system in Java, ensuring 100% test coverage with JUnit.
• Created reusable table components for the user management system using HTML, CSS, and TypeScript in frontend development.
• Detected all potential bugs before shipment by achieving 100% test coverage for the Construction Cost Management System using Java and manual testing.
• Conducted thorough user testing and diligently reported bugs via JIRA.
• Removed all functional bugs by designing test cases and meticulously verifying test results for the construction cost management system using MySQL and JIRA for manual testing.

Skills: Java, TypeScript, Node.js, MySQL

• CICCC - Cornerstone International Community College of Canada
  • Web and Mobile Application Development Diploma, Web and Mobile App Development
  • Jan 2022 – Dec 2023
• Meiji University
  • Bachelor of Interdisciplinary Engineering, Interdisciplinary Mathematical Sciences
  • Apr 2016 – Mar 2020

• AWS Certified Solutions Architect – Associate
  • Mar 2024 – Mar 2027
• AWS Certified Cloud Practitioner
  • Sep 2023 – Sep 2026
• IELTS General Training O.A 8.0
  • Aug 2023 – Aug 2025
• Hacktoberfest 2022 - OSS contributions
  • Oct 2022
• TOEIC Listening & Reading 825
  • Mar 2021