05/2025 – Present · Ho Chi Minh
Donuts Co., Ltd. (株式会社Donuts)
Full Stack Developer
Jobcan Payroll Management – Vietnam (Cross-functional Team of 5)
- Designed and implemented Vietnam Personal Income Tax declaration system (Form 05/KK-TNCN — monthly withholding, Form 05/QTT-TNCN — year-end finalization), handling income aggregation, deduction rules, payroll-tax reconciliation, and multi-branch reporting for enterprises with 1,500+ employees.
- Built full-stack workflows for creating, listing, searching, validating, and exporting tax declarations using Ruby on Rails (RESTful APIs, service objects, Pundit authorization) and React/Redux (redux-form) on the frontend.
- Provisioned AWS infrastructure using Terraform (SQS, IAM, compute, networking).
- Built asynchronous processing pipelines using Shoryuken and Amazon SQS; leveraged ElasticMQ for local queue emulation to support development and integration testing.
- Containerized application services with Docker and implemented CI/CD pipelines using CircleCI for automated build, unit test.
Enterprise Web Ecosystem: Donuts Corporate & Jobcan Product Suite (Team Lead)
- Led a 3-member engineering team using Agile/Scrum methodologies through the full SDLC, delivering scalable TypeScript solutions based on Japanese business requirements.
- Architected automated CI/CD pipelines and hosting using AWS Amplify for Next.js applications, enabling secure, zero-downtime releases.
- Optimized performance using Next.js (SSR/SSG) and advanced caching, significantly reducing page load times and improving SEO metrics.
- Mentored fresher engineers via rigorous code reviews and technical training, boosting team sprint velocity and independent problem-solving.
Ruby on Rails · Next.js · Microservices · AWS · TerraForm



