Full-Stack Engineer

Mobile. Web. Backend.Every layer, one engineer.

From Flutter mobile apps to web frontends and Python/AWS backends — I handle requirements, design, build and operations myself, so nothing is lost in handoff and delivery stays fast and consistent.

Get in touch

43

Projects delivered

5.0

Average rating

Platinum

Coconala top rank

1

Engineer covering every layer

Portrait of Sena
Profile

One engineer, start to finish.

I'm Sena Aoyagi of Sena Lab. After N High School's general commuting course, I'm now a first-year student in the Department of Information Systems at Bunkyo University.

I've been obsessed with making things since elementary school, and programming found me in middle school when I started running a Minecraft server. Watching people enjoy what I'd built, and improving it from their feedback, is where I found the joy that set me on this path.

I don't limit myself to one specialty — I pick whatever technology best fits a project's problem. Combining what I've learned across mobile, web and server work lets me look at any one project from multiple angles.

To put that to use on real projects, I care as much about clear communication as about code. Knowing how hard technical work is to explain to people in other roles, I try to listen closely to what's actually needed and propose things anyone can understand.

What I do

Capabilities

These are common examples — for anything not listed here, just ask; most needs can be accommodated.

01

Mobile App Development

iOS and Android apps designed, built and shipped with Flutter. Strong in Firebase integration and modern UI implementation.

02

Web Systems & Sites

From corporate sites to web applications with complex requirements — I pick the right stack for each project (often Next.js) and build end-to-end, front to back.

03

Automation & Efficiency Tools

Scraping, API integration, Excel automation and more — I pick whatever stack fits best and deliver practical, maintainable tools built to keep working in the field.

Works

Selected work

Project with the University of Tsukuba
N High × Tsukuba

Project with the University of Tsukuba

Built an SMS authentication system for the University of Tsukuba's Department of Information Science, and wrote the accompanying technical article.

One of Japan's Largest Minecraft Servers
Personal project

One of Japan's Largest Minecraft Servers

Planned, founded and operated a Minecraft server with one of Japan's largest monthly player bases — infrastructure through operations, solo.

Enterprise Web & App Development
Commissioned dev

Enterprise Web & App Development

Contracted web and app development for multiple companies (details under NDA) — including one app that passed 100,000 downloads.

Wallpaper Resize
Personal project

Wallpaper Resize

A personal app that resizes images into an optimal wallpaper for a device's screen resolution (no longer maintained).

View on GitHub →
Ruby Tools
Personal project

Ruby Tools

Built and ran a site bundling 20 web tools in one place (retired January 2025).

NominVPN
Personal project

NominVPN

Built and operated a server for the University of Tsukuba's VPN Gate project — 85,977 cumulative users at 100% uptime, never once down (retired January 2025).

Skills

Tech stack

Languages

PythonDartTypeScriptJavaScriptHTML/CSS

Frontend

FlutterReactNext.js

Backend

FastAPIDjangoNode.js

Database

MySQLPostgreSQLCloud Firestore

Infra / Cloud

AWSFirebaseGCPDockerUbuntu

Tools

GitGitHubVS Code
Pricing

Per-project estimates

Flutter App Development

¥100,000〜

iOS/Android, design through launch

Web System Development (Next.js)

¥100,000〜

Corporate sites through business systems

Python Automation

¥30,000〜

Scraping, API integration, Excel automation

Ongoing contracts also available — ¥3,000/hr〜 or ¥100,000/mo〜

Testimonials

From past clients

“Always incredibly courteous to work with — even when my own delays held things up, he stayed consistently understanding. I'd love to keep working together on future projects.”

— Chongyi

“Brought him a request with complex spec changes, and once again he delivered exactly what I needed with real technical skill — even fixing details I only noticed afterward, without hesitation.”

— Kame

“Thoughtful support throughout, and a beautifully clean result — very happy. Will reach out again.”

— KDO2017

Contact

Let's talk about your project

Happy to talk even before your spec is finalized — tell me what you're trying to achieve and I'll propose the right approach and roadmap.

Or reach out by email

hello@senalab.jp

Let's talk about your project.