Sorah Fukumori

Software Engineer
Also known as: sora_h, soraher, そらは, 福森空葉

Ruby committer and a Rubyist, currently working as a SWE on Developer Experiences and corporate IT. Interested in IP network, distributed systems, identity and authentication. Sometimes powering conference with Wi-Fi, organizes a Ruby conference, and operates non-commercial BGP AS.

Lives in Tokyo, Japan.



Professional Experiences

Cookpad Inc.

Software Engineer (Developer Experience)
April 2012 - present
  • Cookpad is the largest recipe sharing website in world.
  • Developer Productivity Team

    July 2020 - Present
    • Developer Productivity team focuses on developers platform, owns responsibility for developer experiences.
    • (Site Reliability Team has been splitted to Site Reliablity team and Developer Productivity team on July 2020)

    IT, Corporate Engineering Team

    October 2019 - Present
    • Since October 2019 I'm officialy belonging to corporate engineering, IT admin team as an additional role, along with SRE. I'm helping IT with engineering around enterprise authentication and authorization platform (SAML, LDAP, Active Directory, Jamf/Intune MDm) and enterprise network.
    • Also supporting IT team in our global team - employees across the globe, connecting Japanese-based IT admin team each other.

    Site Reliablity Engineering Team

    May 2015 - June 2020
    • Site Reliablity Engineering, SRE Team (formerly known as Infrastructure Team) is responsible to site reliablity and aims to automate operations as much as possible, and keep the infrastructure up to date.
    • The major project I've done here is building a infrastructure for our global services from scratch. Achieved with modern AWS services and features (2014).
    • In 2019, I've built a IoT infrastructure for Cookpad Mart to enable Raspberry Pi fleet used for fridges and label printers with SORACOM. (blog post)
    • (Developer Productivity Team were merged into SRE team on January 2019. But splitted again on July 2020)

    Development Infrastructure Team

    April 2012 - April 2015
    • Development Infrastructure Team aims to improve developer experience (DX).
      Building and maintaining internal tools, in-house platform, and dealing with technical debts...
    • Starting 2015, we're migrating one big monolithic web application to microservices like architecture, many small applications.
    • I developed Mamiya, Envchain at this team.



November 2018


September 2018
  • A web application provides AWS IAM access key self service and federated login to AWS management console, based on IAM users.


December 2017
  • Web-based FIDO U2F helper for CLI operations (e.g. SSH logging in)


December 2016
  • Wrapper for Itamae to make it easily use with a lot of servers by inventory.


June 2016
  • A tool to codificate a configuration of Fastly CDN in Ruby DSL.


February 2016
  • A simple, effective ACME client to use with many servers and a cloud.
  • ACME Protocol is used at Let's encrypt for automating SSL certificate issuing. Acmesmith is the simplest client that works with several cloud providers for securing keys.


September 2015


September 2014


June 2014


January 2013
  • Simple blog system built up with Sinatra, written in Ruby.

See more at my GitHub and my profile.




Conference organizer, Wi-Fi NOC
September 2017 - present


Committer (developer)
February 2011 - present
  • Contribute as a committer of Ruby programming language.
  • Also participate as a member of official web site editorial team.

IOI 2018 (30th Int'l Olympiad in Informatics)

Tech lead, Host Technical Committee
July 2017 - September 2018


Organizer and problem writer
August 2014 - November 2014

March 2011 - December 2011
  • provided informations for victims of 3.11 Japan disaster.
  • I re-built Twitter crawler to improve performance, and added location based search using GPS for mobile devices.

And more

Skills, Expertises


Honors, Awards and Prizes

ISUCON9: 1st place

September 2019 - November 2019

AWS GameDay at re:Invent 2019: 1st place (Afternoon)

December 2019

ISUCON5: 2nd place

September 2015 - November 2015

第 7 回 日本OSS奨励賞 (Japan OSS Contributors Award)

March 2012


Kyoto university Microcomputer Club (KMC)

Member, Sysadmin
August 2014 - present


Utsunomiya-shi Yohoku Junior High School '12

April 2009 - March 2012



An Interview
June 2012
  • @ttmtmy interviewed me at WEB+DB PRESS Vol.69 "シューカツ女子ともよの会社訪問記 知りたい!あの人のはたらきかた"


An Interview
April 2011