Full-Stack Developer · Tokyo, Japan

I build and run web systems end-to-end.

Full-stack engineer at a Japanese financial-services company, leading a team of six. I cover the whole lifecycle — requirements, design, implementation, release, and operations on AWS.

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3+ yrs
Engineering: 6
Team members led: AWS SA Pro
Certified: 915
TOEIC L/R

Experience

Where I've worked

Apr 2023 — Present

Full-time

Full-Stack Engineer / Development Lead

Aiful Corporation — Consumer & business finance

Lead a six-member team building a paperless business-loan platform: a customer-facing document submission form and an internal review & management system, integrated with internal systems and external services via APIs.
Own the full lifecycle in an agile team — requirements definition, design, implementation, testing, release, and operations & maintenance.
Built CI/CD pipelines with GitHub Actions and automated E2E testing; run AWS deployment, monitoring with New Relic, and incident & vulnerability response.
Promoted to development lead nine months into my engineering career; manage tasks, review code, and provide technical support for the team.
Drove the in-housing of vendor-dependent work, leading from planning through execution; improved on-time delivery by surfacing schedule risks early.

Dec 2020 — Jan 2023

Full-time

R&D Engineer

Landes Co., Ltd. — Precast concrete manufacturer

Researched concrete materials and environmentally friendly concrete products.
Presented research results at industry forums and co-authored technical papers for the Next-Generation Precast Construction Technology Research Association.

Featured project

Business-loan web platform

A web system that digitizes business-loan operations end-to-end, replacing paper workflows. Customers submit screening documents through a web form; staff manage submissions and screening status in an internal admin system. API integrations with internal systems and external services streamline the screening process.

Highlights

Designed and built both the customer-facing submission form and the internal review system.
Automated E2E testing and built the CI/CD pipeline, raising release confidence and speed.
Adopted AI development tools (Claude, GitHub Copilot) across the team to improve efficiency and code quality.
Operate the production environment on AWS — deployment, monitoring, and user-inquiry support.

Skills

Tech stack

Frontend

HTMLCSSJavaScriptVue.js

Backend

JavaSpring BootPython

Database

MySQL

Cloud & Infra

AWSDockerNginxGitHub ActionsNew Relic

AI dev tools

ClaudeGitHub Copilot

Tools

GitWordExcelPowerPoint

Certifications

Feb 2026AWS Certified Solutions Architect — Professional
Sep 2025AWS Certified Developer — Associate
May 2025Fundamental Information Technology Engineer (FE)
Dec 2024TOEIC L/R — 915 / 990
Sep 2024AWS Certified Solutions Architect — Associate
Mar 2024LPI Linux Essentials
Sep 2023AWS Certified Cloud Practitioner
Jul 2021JLPT N2 (Japanese Language Proficiency)

About

From concrete R&D to code

I started my career as an R&D engineer at a precast concrete manufacturer, where I learned to solve problems methodically and work closely with cross-functional teams. Two years in, I discovered software development — and taught myself into a full-time engineering role.

My biggest strength is adapting fast in unfamiliar territory: nine months after switching careers I was leading a development team. I keep that pace through constant learning — certifications, technical news, and hands-on experiments with new tools, shared with my team.

I aim to be an engineer who bridges technology and business — someone who can take a product from requirements to operations, and bring others along the way.

Languages: Japanese (business — JLPT N2) · English (TOEIC 915)

Contact

Let's talk

I'm open to full-stack opportunities. The fastest way to reach me is email — I usually reply within a day.

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