Hi, I'M KOSEI

PROFILE

Kosei Ayabe

Hi, I'm Kosei — a software engineer currently based in Canada.
I was born in 1997 in Shizuoka, Japan, and studied computer science at university.
After graduation, I joined a major system integration company, where I worked as a systems engineer for about two and a half years.
In January 2023, I decided to take the leap and started my career as a freelancer.
Outside of work, I love traveling, saunas, reading books, and enjoying manga and anime.
I'm also into board sports like skateboarding, surfing, and snowboarding.
Recently, I've been studying English a lot.

SKILL

Application Development C# / .NET

5 years 90%

Application Design & Development

Experienced in application development using the .NET framework.
Capable of designing and building a wide range of systems including front-end, back-end, and API development.

Database Engineering Databases

5 years 90%

Database Design & Performance Optimization

Experienced in database design, performance optimization, query development, and server operations.
Capable of working with multiple database technologies including relational (RDB) and NoSQL systems.
Able to handle all aspects of database operations.

Front-End Development HTML / CSS

5 years 80%

Responsive Web Interface Development

Experienced in building responsive web interfaces and translating design into functional implementations.
Capable of scratch development for websites and landing pages, as well as modifying existing sites.

Full-Stack Web Development JavaScript / TypeScript

3 years 70%

Interactive Web Application Development

Experienced in web application development using JavaScript and TypeScript.
Capable of front-end feature development including API integration, data processing, and UI implementation.

AI-Assisted Development AI Tools

2 years 70%

Efficient Development with AI Tools

Experienced in leveraging a variety of AI tools and LLMs to enable fast and accurate development.
An early adopter and heavy user of AI technology, I stay up to date with the rapidly evolving landscape by continuously keeping an antenna up for the latest developments.

CMS Development WordPress / WooCommerce

3 years 90%

CMS & E-Commerce Development

Experienced in building and customizing websites using WordPress and WooCommerce.
Capable of developing custom plugins and integrating external services.

Cloud Infrastructure & Deployment AWS / Vercel / Cloudflare

2 years 60%

Cloud Deployment & Infrastructure Management

Experienced in deploying and operating applications in cloud environments using AWS, Vercel, Cloudflare, and other services.
Capable of evaluating appropriate tech stacks and infrastructure configurations based on system requirements, and handling everything from environment setup to operations.

Modern Web Frameworks React / Next.js

1 year 50%

Full-Stack Development

Experienced in building modern web applications using React and Next.js.
Capable of component-based UI development and server-side rendering.

Backend as a Service Supabase

1 year 50%

BaaS & Backend Integration

Experience building backend systems using Supabase, including authentication, database management, and API integration.

Design & Image Editing Adobe Photoshop

3 years 50%

Image Editing & Visual Design

Experienced in image editing, asset creation, and basic UI design support using Adobe Photoshop.

HISTORY

Let's explore my life!

1997

Born in Shizuoka

Born in a small town called Kannami in eastern Shizuoka.
As a kid, I was always outside or playing video games. Got hooked on skateboarding in junior and senior high.
I played volleyball in school clubs and was good at academics—at least until junior high.
Around that time, I started vaguely dreaming about running my own business someday.

2016

Entered IT Faculty

As a middle schooler, I was blown away when I first got my hands on an iPod Touch and iPhone.
Fascinated by the rapid spread of the internet, social media, and smartphone apps, I decided I wanted to become an engineer.
In high school, I was fully focused on sports and my grades slipped badly,
but I buckled down for entrance exams and managed to get into my top-choice university.

2020

Graduated and Started Career

Graduated and joined a major system integration company as a new graduate.
Just as I started my career, COVID-19 hit and I began working fully remotely.
Over the next two and a half years, I moved around Japan—Chiba, Kumamoto, Hiroshima.

2022

Became a Freelancer

Having joined the company to build my professional experience, I left after about two and a half years.
I had always wanted to work in Tokyo, so I moved there after quitting and started out as a freelance engineer.
I soon realized that technical skills alone weren’t enough to stand out in the freelance world.
After a lot of soul-searching, I set my sights on learning English and working as an engineer abroad.

2024

Studied in Cebu

While continuing to study English alongside freelance work, I hit a wall with growing in Japan.
I made the decision to study abroad and spent three months in Cebu, Philippines.
Living overseas for the first time and connecting with international friends was so much fun
that I decided to go on a working holiday the following year.

2025

Working Holiday in Canada

With Silicon Valley—the heart of global tech—close by in the U.S., I decided Canada was the ideal place to grow both my technical and English skills.
I started living in Vancouver in July 2025.
By a stroke of luck, I landed an engineering job in December 2025,
marking the start of my long-awaited career as an engineer abroad.

WORKS

FLOWER SHOP HANA*HANA

This is a flower shop located in Kannami Town, Shizuoka, my hometown.
I was in charge of designing and developing the website from scratch using WordPress.

negura campground

This is a campsite based in Kannami Town, Shizuoka, my hometown.
I built the entire website from scratch using WordPress.

Queue management sysytem

An app I built to replace the paper-and-pen waitlist system at a restaurant I worked at during my working holiday in Canada.
Built with JavaScript and Firebase, it allows staff to share queue status in real time.
Although it was not adopted for full operation, the app was tested in-store and received highly positive feedback from both staff and the manager.

IELTS Writing Lab

Built from my own experience preparing for IELTS, where I felt the lack of a realistic, exam-like practice environment.
The app brings together everything I wanted as a test-taker: practice questions, a customizable text editor, a timer, AI-powered scoring and detailed feedback, and a spell-checker with a personal word registry.
Every feature was shaped by firsthand needs, with the goal of building the most complete IELTS Writing prep tool I could.

CONTACT

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