# Overview

![](https://github.com/yagi-eng/yagi-eng/blob/master/img/just-do-it.png?raw=true)

### Main

| key    | value                                                                                                                                                                                                                                                                                                                                                                   |
| ------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Name   | Kohei Yaginuma                                                                                                                                                                                                                                                                                                                                                          |
| Github | [@yagi-eng](https://github.com/yagi-eng)                                                                                                                                                                                                                                                                                                                                |
| Qiita  | <p><a href="https://qiita.com/yagi_eng">@yagi\_eng</a><br>Trending multiple times, Highest daily ranking: #1<br><a href="http://qiita.com/yagi_eng"><img src="https://qiita-badge.apiapi.app/s/yagi_eng/posts.svg" alt="My Qiita posts"></a> <img src="https://qiita-badge.apiapi.app/s/yagi_eng/contributions.svg" alt="My Qiita contributions"><br>※Moved to Zenn</p> |
| Zenn   | [@yagi\_eng](https://zenn.dev/yagi_eng/books)                                                                                                                                                                                                                                                                                                                           |
| note   | [@yagi\_eng](https://note.com/yagi_eng)                                                                                                                                                                                                                                                                                                                                 |
| X      | [@yagi\_eng](https://x.com/yagi_eng)                                                                                                                                                                                                                                                                                                                                    |

### Sub

| key                | value                                                                                                                                                                                                                                       |
| ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Wantedly           | [@yagi\_eng](https://www.wantedly.com/id/yagi_eng)                                                                                                                                                                                          |
| Speaker Deck       | [@yagieng](https://speakerdeck.com/yagieng)                                                                                                                                                                                                 |
| Instagram          | <p><a href="https://www.instagram.com/yaginu_travels_around/">@yaginu\_travels\_around</a><br>Travel posts<br><a href="https://www.instagram.com/yaginu_nakame_lunch/">@yaginu\_nakame\_lunch</a><br>Gourmet picks around Kamakura area</p> |
| MBTI               | [INTJ](https://www.16personalities.com/ja/intj%E5%9E%8B%E3%81%AE%E6%80%A7%E6%A0%BC), but [changes frequently](https://x.com/yagi_eng/status/1948613914440106052)..                                                                          |
| Favorite Languages | Go                                                                                                                                                                                                                                          |
| Interests          | AI, working at startups, building and scaling engineering organizations                                                                                                                                                                     |
| Hobbies            | Traveling abroad, muscle training, surfin, swimming, marine activities, gaming                                                                                                                                                              |

### Summary

I began my career in software development through a two-year internship at a startup when I was an university student. In 2017, I joined a major systems integrator as a new graduate, where I successfully led a ¥100 million (\~$1M USD) project as a project manager in my second year.

In 2019, I transitioned to freelancing. Later in 2023, I co-founded an EdTech startup and served as CTO and tech lead, where I was responsible for building and scaling the product and the engineering team. As of 2025, I’m once again working as a freelance technical advisor, supporting multiple clients with their technology and product development.

I have led development across a wide range of domains including web apps, mobile apps, dApps, and cloud infrastructure. My core strengths lie in backend development, team management, and early-stage technical leadership. I'm particularly experienced in supporting startups and new product initiatives—offering guidance on technology selection, architecture design, and project direction.

Having worked at a large enterprise with over 6,000 employees, I am also comfortable navigating cross-department collaboration and managing large-scale projects with multiple stakeholders.

In addition to client work, I also pursue personal projects and technical outreach, including:

* Developed a dApp that generates NFT art based on heart rate data
* Built a LINE bot for restaurant search (400+ registered users)
* Gave a solo tech talk in front of 120+ attendees
* Regularly publish technical articles on Qiita and Zenn (multiple trending posts, ranked #1 daily)

Recently, I've been particularly interested in generative AI, and I’m actively exploring how to apply AI agents to both workflows and product features.

If you're looking for support in software development or technical leadership, feel free to reach out.

[The detail is here](https://yagi-eng.gitbook.io/resume/)

日本語版もこちらにあります。


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://yagi-eng.gitbook.io/resume/readme.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.