A server-side engineer working mainly with Ruby on Rails and AWS on web services.
Since 2011 I have launched 8 services, covering planning and technology selection as well as running the team: hiring, 1-on-1s, and performance reviews.
From programmer to engineering manager and CTO, I work across both development and operations on technology choices and team building that lead to business growth.
Improved a response time of about 50 seconds to about 400 ms, and a home page of about 6 seconds to 200–400 ms
About
I am on loan from DeNA Co., Ltd. to Welcompass Inc., working on product development for “Tsunaken.”
I dropped out of technical college and started my career in large-scale systems integration for finance and retail. After building HPC clusters, I moved on to in-house web services in social games, entertainment, and education. I have worked as a programmer, lead engineer, engineering manager, and CTO.
My experience goes beyond development to operating and maintaining networks, servers, and databases. I do not lean toward either development or operations; I am good at thinking about the whole system, and the whole business behind it.
I have also worked on optimizing application performance as services grow.
I am often involved in launching new services, and have launched 8 of them since 2011. My work covers planning, requirements definition, and technology selection, as well as running the team: hiring, 1-on-1s, and performance reviews.
My domains are broad: finance, retail, manufacturing, government, social games, education, and blockchain games. In each industry I have learned the domain from scratch to get the work done.
My life goal is to grow a service that is used by more than a million people a month and lasts for ten years.
Work inquiries
I take on inquiries such as the following.
Server-side development of web services, mainly with Ruby on Rails
Infrastructure design and operations with AWS and Terraform / CDK
New products, from launch through stable operation
Application performance optimization as a service grows
As a senior engineer, supporting the growth of the team and the business with my past experience while backing younger managers.
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Welcompass Inc. (on loan)
Product development for “Tsunaken” and AWS cost reduction. Improved a response time of about 50 seconds to about 400 ms.
AWS, CDK, Go, TypeScript
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Pococha
Development and operations of a live-streaming app: feature development, day-to-day improvements, and support for Scrum teams.
Ruby on Rails, AWS, Aurora, Redis, Lambda, Terraform, Kotlin
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Freelance Programmer
Development of a blockchain-based game service centered on Go and Google Cloud: backend development, CI/CD, and building the production environment.
Go, Google Cloud Spanner, Redis, Terraform, TypeScript
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Globis Corporation Engineering Manager / Engineer
In charge of a new education product, from development through launch and operations.
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Engineering Manager
For the launch of a learning management system (LMS) sold as SaaS, handled business planning, budget negotiation, requirements definition, technology selection, code review, and building the CI/CD environment. Also wrote job descriptions for backend engineers and product managers, interviewed candidates, and ran 1-on-1s and performance reviews.
After launch, worked on operating and maintaining a video learning service, including integration with the core ERP system and a major Rails upgrade (6 to 7).
Wrote code as needed and also served as Scrum Master. (10 people)
Ruby on Rails, GraphQL, React, TypeScript, AWS, Aurora, Redis, Heroku
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Freelance (contract)
For a new learning management system (LMS) used in training products, handled requirements definition, technology selection, development, and building the CI environment, and rotated as weekly Scrum Master. From July 2019, started work on the SaaS version of the LMS.
Ruby on Rails, GraphQL, React, TypeScript, AWS
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Giraffe, Inc. Engineer / CTO
Transferred from Startup Lab to join as an engineer, and later became CTO. At a startup from seed to Series A, handled development, operations, and engineer hiring, and led a team of 18.
Developed and operated comparison and buyback media sites, migrated to AWS, directed development of a new service (a marketplace), handled account migration for an acquired service and a DDoS attack, and set up an internal study-group program. Improved a home page that took about 6 seconds to 200–400 ms.
Also defined hiring criteria, wrote an interview manual, trained interviewers, and held monthly 1-on-1s with team members.
Ruby on Rails, AWS, TypeScript
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Startup Lab, Inc. Engineer
Built and operated Magi, a flea-market service specialized in trading cards. Transferred to Giraffe in March 2017 after the CEO invested in Giraffe.
Ruby on Rails, AWS, Terraform
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SKIYAKI Inc. Manager
As manager of a team of about 10, built new services, coordinated with the business side, handled the IPO audit, and reduced infrastructure costs.
Built a log visualization platform, set up a reference database for internal systems with MySQL multi-source replication, and automated billing operations.
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Pokelabo, Inc. Engineer to Senior Engineer
Joined as an engineer and took part as a lead engineer in the development and operations of four social games on Mobage and iOS. Later became a senior engineer working across internal services.
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Infrastructure development and operations for internal services
Worked across internal services as an infrastructure engineer: server setup and operations, KPI log batches, and building an access-log collection and analysis platform.
Added row-level sharding to an existing application (to handle a large-scale promotion) and designed and implemented an API for growth hacking.
PHP, MySQL, MongoDB, fluentd, RabbitMQ
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Development and operations of an iOS social game
As lead engineer, handled server design, service development in PHP, and support for iOS client development.
PHP, MySQL, memcached, Unity, cocos2d-x
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Development and operations of an iOS social game
Handled service development in PHP and iOS client development.
PHP, Objective-C, MySQL, memcached
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Development and operations of a Mobage social game
As lead engineer, handled development and operations of the service and its events, and created schedules and managed progress.
PHP, MySQL
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Development and operations of a Mobage social game
Handled development and operations of the service and its events.
Joined as a full-time employee and developed and operated systems for manufacturing, government, research institutions, universities, and school corporations through contract engineering (SES).
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A university’s curriculum planning system
Worked on the course management feature.
PHP
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A manufacturer’s internal intranet (on site)
Handled everything from server setup to business application development and operations. Also made technical proposals.
PHP, MySQL, Oracle, CentOS
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A school corporation’s admission results system
Migrated the website to SSL and built the admission results system, from requirements definition through deployment.
PHP, MySQL
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A government agency’s GIS portal site
Selected the CMS to use and handled detailed design.
WordPress, MySQL
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Operations and maintenance for government and research institutions
Maintained Windows servers and clients, operated web systems and migrated data, and maintained database servers.
Built a backup system and mirror environment, and trained new hires.
Oracle, RHEL, CentOS, FreeBSD, Windows Server
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Short-term development and testing projects
A web reservation feature for a facility, and back-office features for the core system of a fresh-flower gift business.
Legal compliance for a manufacturer’s environmental system, and software testing for telecommunications equipment.
PHP, VB.net, HiRDB, Solaris
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Bakuhatsu Kenkyusho Co., Ltd. Programmer
Development and sales of parallel computers: building Linux HPC clusters, performance measurement, and building the company network.
Linux
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Alphatech Co., Ltd. Programmer
On a foreign exchange back-office package for a major IT vendor, developed a program that automatically runs online applications, and maintained existing online and nightly batch processing.
Solaris, Symfoware
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Freelance Programmer
Took part, as a contractor, in developing and maintaining systems for financial institutions and a convenience store chain.
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A city bank’s connection to the Bank of Japan systems (securities trading application)
Handled development.
Pro*C, Oracle, IBM MQ, Solaris
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A convenience store chain’s ordering system
Tested batch applications built on a proprietary framework.
C, Oracle, HP-UX
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A major IT vendor’s foreign exchange back-office package
Handled detailed design, development and maintenance of the online (server-side) and nightly batch processing, and system integration with the mainframe (sending and receiving business messages). Also served as sub-leader. (8 people)
C, awk, shell scripts, Symfoware, Solaris
Other
Education
Ibaraki National College of Technology, Department of Electronic Control Engineering (left without graduating, )
Community
Volunteer organizer for YAPC::Asia. Gave a talk at a technology event in 2017