Backend / Infrastructure / Security
Technical Expertise
- Backend: Python (FastAPI), TypeScript, Go, PHP
- Infrastructure: AWS, Kubernetes, Terraform, Ansible
- Security: Vulnerability Assessment, Threat Analysis, Incident Response
Professional Experience
- Contract & internship experience at 7 companies
- Led AWS App Runner migration project
- AI Agent Development (Healthcare x LLM)
Works
FastDOCTOR, Inc. Backend Engineer / AI Engineer 11/2024 ~ Present
Responsibilities
- AI agent development
- Healthcare x LLM PoC development & evaluation framework
Key Achievements
- Built medical record transcription PoC and evaluation framework
- Developed and deployed AI agent PoC for medical administration
- Technical evaluation and selection of LLM frameworks (Mastra/LangGraph)
Tech Stack
Armoris Inc. Security Research Intern 10/2020 ~ 03/2021 10/2022 ~ Present
Responsibilities
- Vulnerability & security tool assessment
- Threat intelligence analysis
Key Achievements
- Analyzed phishing campaigns targeting financial institutions (94 URLs analyzed, mapped attack infrastructure)
- E-commerce site defacement incident analysis
- AiTM attack & phishing framework (Evilgophish/Evilginx) validation
- SSH vulnerability scanner (SSHamble) assessment
Tech Stack
meing Inc. Backend Engineer / Infrastructure Engineer 10/2023 ~ Present
Responsibilities
- Backend API development
- Infrastructure design & re-architecture
Key Achievements
- Infrastructure setup using AWS CDK
- Salesforce/Stripe integration
- Re-architecture for improved maintainability through dependency simplification and separation of concerns
Tech Stack
CoPalette Inc. Backend Engineer / Infrastructure Engineer 10/2024 ~ Present
Responsibilities
- Infrastructure migration & CI/CD setup
- Backend feature development
Key Achievements
- Implemented recommendation and organizer features
- EC2 to App Runner migration (see tech article for details)
- CI/CD pipeline setup
Tech Stack
Togetter Inc. Backend Engineer 10/2022 ~ 03/2024
Responsibilities
- Maintenance and development of existing services
Key Achievements
- Backend feature additions and bug fixes
Tech Stack
NewBizz Inc. 02/2023 ~ Present
Prokids Inc. 10/2019 ~ 03/2021 03/2022 ~ 11/2022
Short-term & On-site Internships
- Sansan, Inc. (On-site Internship)9/16/2024 ~ 9/27/2024 2/13/2025 ~ 3/28/2025
- Recruit Co., Ltd. RED TEAM (On-site Internship)10/3/2024 ~ 11/1/2024
- Nikkei Digital Edition Internship8/15/2022 ~ 8/19/2022
- LINE Corporation Hackathon Internship8/16/2023 ~ 9/1/2023
- STORES Tech Camp (Short-term Internship)9/4/2023 ~ 9/15/2023
Projects
Home Server Infrastructure
Personal home server setup. Built Kubernetes cluster on Proxmox virtualization. Practicing IaC and GitOps with Terraform + Ansible.
Challenge
Acquiring production-grade infrastructure skills, building reproducible environments with IaC, achieving declarative operations with GitOps
Role
Solo project (all infrastructure design, implementation, and operations)
Outcome
Gained production-level Kubernetes operational experience. Ensured environment reproducibility through complete IaC. Streamlined operations with declarative GitOps management.
EC2 to App Runner Migration Project
Migrated hackathon platform infrastructure from EC2+Docker to AWS App Runner. Achieved reduced operational overhead and CI/CD automation.
Challenge
Manual SSH-based SQL migrations, scattered secret management, unstable deployment flow
Role
Backend & Infrastructure Engineer at CoPalette
Outcome
Fully automated deployments, significantly reduced operational overhead, improved migration stability, established CloudWatch-centric monitoring
Coding-Remote
Remote tool approval and session management system integrating Claude Code with Discord. Enables file editing and command execution approval via Discord.
Challenge
Continuing Claude Code sessions outside VSCode, enabling remote coding from mobile devices
Role
Solo project (planning, design, and implementation)
Outcome
Built session management and Discord UI-based approval workflow. Released as OSS under MIT license
String Art Simulator
Software for creating string art mandala designs. Enables detailed simulation of color schemes and patterns.
Challenge
Performance optimization for complex geometric pattern rendering, intuitive UI/UX design
Role
Solo project (planning, design, and implementation)
Outcome
Won U-22 Programming Contest 2019 Award and NJK Award
Skills
Python
Extensively used for server-side processing such as APIs, web scraping, and image processing. My go-to language for quick tools and prototypes.
Go
Used for personal Digital Signage v2 project, web app backends, and backend development at NewBizz Inc.
TypeScript
Used for frontend development of web apps like String Art Simulator and 2434units.com. Also used for backend development with NestJS and Prisma.
PHP
Used for backend development.
Docker
Used for setting up development environments and deployments.
AWS
Infrastructure provisioning and operations using AWS CDK with services like ECS, Aurora Serverless, ECR, and S3.
Proxmox
Nginx
NestJS
MariaDB
PostgreSQL
Prisma
Raspberry Pi
Awards
- Fun micro:bit Contest 2019 - Special Award "Remote Insecticide Spray Vehicle"
- U-22 Programming Contest 2019 - Award & NJK Prize "String Art Mandala Color Simulator"
- Minna no Raspberry Pi Contest 2019 - Raspberry Pi Foundation Award "Digital Signage with Raspberry Pi"
- Minna no Raspberry Pi Contest 2021 - Student Award "EnigmaPi - Detailed Enigma Reproduction"
- Tokyo Tech Student Contest: Master ChatGPT! Vol.1 - App Development with GPT-4 Technology Award for Transcription Improvement (Team: pyてょん3.0)
- Digital Agency Legal API Hackathon Business & Legal Award (Team: pyてょん3.0)
Certifications
- Registered Information Security Specialist Examination (RISS)
- Network Specialist Examination
- Applied Information Technology Engineer Examination
- Fundamental Information Technology Engineer Examination
Other Certifications
- EIKEN Grade Pre-1 (English Proficiency Test)
- IT Passport Examination
- J-Test Information Utilization Test Grade 1
- J-Test Information Systems Examination - Programmer Certification
- Japan Kanji Aptitude Test Grade 2
Articles
Media
Hobby & Personal Projects
2434Units.com
Website providing the latest information about VTuber group Nijisanji's units
Digital Signage v3
Digital signage system using Raspberry Pi with Dropbox/Google Drive integration to digitize bulletin boards.
Image2PDF
Web application for combining and converting multiple images into a single PDF file
EnigmaPi
Smart Lock with Raspberry Pi
System to convert existing door locks into smartphone-controllable smart locks.
Presentation Support System
Tool for making presentations more engaging and convenient. Implemented real-time comment streaming overlay on slides.
PS2JPC-BOT
Management bot for the unofficial Japanese community of PC game PlanetSide2, running since 2017. Implements role management, in-game event announcements, server administration, and more.
RC Tank Model Conversion
Tamiya 1/35 scale tank model equipped with Raspberry Pi Zero WH. Controllable via Xbox controller with turret rotation capability.
Spherical Robot
Spherical robot with Raspberry Pi Zero WH housed inside a plastic sphere. Controllable via Xbox controller.
Remote Insecticide Spray Vehicle
Remote-controlled robot (?) for spraying insecticide.