Takashi Masuda (masutaka)

masutaka

This site records the change history of Masutaka, a humble software engineer. The slides I’ve made so far are on Speaker Deck .

The content of this site is licensed under CC BY 4.0 . The sample source code is licensed under Apache-2.0 .

1976/01 ~ 2000/03 Birth ~ School Days

Born in Hamamatsu, Shizuoka, Japan.

I hold a master’s degree from the Graduate School of Agriculture at Utsunomiya University, majoring in Bioproductive Science. Looking back, I wasn’t even interested in agriculture, yet I went on to graduate school simply because I didn’t want to start working… My entrance exam scores were terrible, but back then, students moving up within the same university could squeak by.

Realizing I couldn’t go on like this, I passed the Associate Systems Administrator exam in my first year of graduate school, which gave me just a little confidence.

On the personal side, I bought my first Windows 95 machine in my second year of university. Upgrading Windows and reinstalling it regularly was something of a hobby (?). After Windows 98, I recall finally settling on a dual boot of Windows NT 4.0 and Plamo Linux.

2000/04 ~ 2011/04 Metatechno Inc.

As an embedded software engineer, I mainly worked on the development and maintenance of Canon laser printers.

Until around 2005, I was in charge of the firmware’s rendering engine and device drivers for image compression. After that, I built a nightly automated test environment1 for the rendering team and created handy libraries for development. Traces of that time remain at https://github.com/masutaka/imgdiff .

In parallel, I volunteered to maintain and build about 100 Solaris 9 servers in the company’s clean room. I was given free rein, so I kept running make install for my favorite tools like Emacs, Ruby, and OpenLDAP on NFS.

2011/05 ~ 2013/11 Langrich Inc.

On a sudden impulse, I left Metatechno after 11 years and joined an online English conversation startup as its first employee. [2011-04-22-1]

My job as a software engineer stayed the same, but embedded and web development, especially at a startup, had completely different cultures. I remember getting through on sheer momentum.

I maintained and operated a reservation system built with CakePHP, worked on replacing it with Rails (which later fell through), and built an OEM version of a now-defunct Recruit service. Learning and mastering Scrum and TDD was a big experience.

At the same time, I took the initiative to set up environments like Jenkins and Redmine, which made me realize once again that I enjoy this kind of work.

2014/03 ~ 2023/01 Feedforce Inc.

After a few months of staying at home and helping an acquaintance with development, I joined Feedforce. [2014-03-09-1]

Here are the company blog posts I wrote until [2023-01-31-1] (in Japanese).

2014/03 ~ 2014/04 DF PLUS + α

Right after joining, I was assigned to a batch service for data feeds.

In parallel, I introduced GitHub, CircleCI, Qiita:Team, and more, which I think sped up development across the company. My experience at my previous job made a big difference.

GitHub in particular: I’ve continued to lead it as an Organization Owner, introducing new features within the company, designing and operating access permissions, and proposing and carrying out security improvements.

2014/05 ~ 2017/04 Social PLUS

I was put in charge as the development lead of a social login service built with Rails. In the latter half, I stepped away from the lead role and worked on improving the AWS infrastructure.

2017/05 ~ 2018/03 DF PLUS

I was transferred back to DF PLUS. This was the first time I used container technologies like Docker and ECS in production.

2018/04 ~ 2020/03 EC Booster

I worked on a service that lets e-commerce shops easily run Google Ads. I started as a backend engineer, and partway through, my main job became improving the development platform, such as CI/CD improvements and performance tuning with a CDN.

Along the way, I studied Heroku thoroughly. I think I was putting out more information about it than anyone else in Japan at the time (in Japanese).

My favorite is this one.
I gave a talk titled “In Search of Batch Processing That Doesn’t Stop on Deploy” at Heroku Meetup #27
Heroku dynos are recreated on every deploy, which restarts batch processing from the beginning, so I worked on avoiding that. I recall someone at Heroku praising (?) me, saying they were impressed I went that far.

It was around this time that I consciously, and on my own initiative, started working like an evangelist: thoroughly learning Heroku, implementing with it, and sharing what I learned.

2020/04 ~ 2023/01 Feedmatic

When the ad operations service decided to adopt Looker , I was entrusted with its design, implementation, and operation as the sole developer.

Until then, I wasn’t a LookML developer, or even a data engineer, but as I learned Looker, I became captivated by it.

I’ve published blog posts about the initial adoption and implementation, and about how things stood a year and a half later (in Japanese).

Since I was developing alone, I tried to keep the number of services as small as possible. I managed to settle on a simple setup: collect all data in an ETL service called Funnel.io , export it to BigQuery, and have Looker reference it.

When developing alone, it’s hard to notice when data breaks, and interruptions are costly, so I wrote thorough LookML tests and even automated them with GitHub Actions.

I also made a point of finding time to share my enthusiasm. I’m very happy that I was able to write niche posts you can’t find anywhere else.
Looker category - Feedforce Developer Blog

2023/02 ~ 2023/08 PayPay Corporation

I joined to make use of my LookML development experience at Feedforce.

I built account request flows for Looker and Tableau, and proposed better ways of developing LookML.

My time there was short, only half a year. [2023-08-03-1]

2023/08 ~ 2025/10 ROUTE06, Inc.

Here are the company blog posts I wrote (in Japanese).

2023/08 ~ 2024/06 Data Engineer

I was assigned as a member of a project implementing embedded QuickSight dashboards. For the data platform, ELT ran dbt on ECS Tasks periodically via AWS Step Functions, and the data lake was Redshift.

In the Tableau dashboard implementation project starting in 2024/01, I was also entrusted with running the data team as its lead. The data lake was Snowflake.

2024/07 ~ 2025/10 OSS Promotion Office

The data team was disbanded, and I was assigned as a member to launch the OSS Promotion Office. I was responsible for promoting open-sourcing of internal products, OSS marketing, and more.

2025/06 ~ 2025/10 Web Application Engineer

I was assigned to prototype an AI chat using a knowledge base and port it to a B2B product.

2025/11 ~ Present A FinTech Company

I joined a FinTech company as a Rails engineer.

I was all fired up to relearn Rails and absorb the business logic with the mindset of a newcomer, but before I knew it, I was assigned to improve the development platform, starting with CI/CD, and I’m now working on speeding up the development cycle.

Few people raise their hands for this kind of work. But strangely, I don’t mind it, and it lets me play to my strengths, so I took it on this time as well.

  1. Handy tools like Jenkins didn’t exist back then, so I wrote lots of Ruby scripts on Windows and built my own automated test environment. ↩︎