RYNK.
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ABOUT RYNK

About RYNK

RYNK is a sole proprietorship based in Sapporo, offering product development, contract development, and IT support for businesses.

R

Founder

Sole Proprietor / Software Engineer

I started building websites in the fifth grade, teaching myself HTML, CSS, and PHP. From there, I expanded into Python, Java, C, and smartphone app development, and today I focus on Flutter, Next.js, Firebase, and AI APIs.

I founded RYNK in 2026 while studying engineering at Hokkaido University. Alongside planning and building in-house products, I take on web and app development and IT support for businesses.

I generally handle everything myself, from the initial conversation through design and implementation. I enjoy independent development, and I like building something that works and improving it from there.

SKILLS

Skill set

Frontend

Next.js / React / TypeScript / Tailwind CSS / HTML/CSS / Figma

Mobile

Flutter / Dart / Swift / Kotlin

Backend

Node.js / Python / PHP / Cloud Functions / REST API / C / C++ / Java

AI & API

OpenAI API / Claude API / Stripe API

Infra

Firebase (Firestore) / AWS / Docker / Linux / Git/GitHub / SQL / PostgreSQL
TIMELINE

Career

  1. 2026

    Founded RYNK

    Founded RYNK as a sole proprietorship while studying at the Faculty of Engineering, Hokkaido University. Began developing in-house products and taking on contract work.

  2. 2025

    Built Tekipa and ShiftMaster

    Started developing Tekipa, a service for students, and ShiftMaster, a shift management service.

  3. 2024-04

    Entered Hokkaido University

    Studied information science at university while continuing independent development.

  4. 2016

    Started building websites

    Began learning web development independently, starting with HTML, CSS, and PHP.

COMPANY

Business Overview

Business name
RYNK
Location
Sapporo, Hokkaido, Japan (details shared upon engagement)
Coverage area
Online: available nationwideOn-site: Sapporo city and nearby areas, depending on details and schedule
Business activities
- Design, development, and maintenance of websites, web services, and business systems- Design, development, and operation of smartphone apps- Feature development and workflow automation using AI APIs- Website updates and inquiry/booking setup- IT support for businesses- Planning and development of in-house products
Founded
2026 (established as a sole proprietorship)