Fumiaki Matsushima
Senior Backend Engineer at Autify
Japan
Summary
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Rockstar🎓
Top SchoolFumiaki Matsushima is a Senior Backend Engineer in Japan with 13 years of experience building reliable server-side systems and shaping developer tooling. He has deep Ruby expertise demonstrated by notable contributions to flagship projects like Ruby on Rails and graphql-ruby, plus practical work on rbs and MongoMapper that improved type handling, thread safety, and association behavior. At companies including Autify and Quipper he has led backend efforts and driven maintainable code and testing improvements while also contributing to large documentation projects like the Japanese Rails Guides. Comfortable working across core libraries and application code, he has a track record of subtle but important fixes—refactoring tests, resolving autoloading edge cases, and refining code generation—that reduce technical debt and improve developer experience.
12 years of coding experience
4 years of employment as a software developer
Bachelor of Technology - BTech, Information Technology, Bachelor of Technology - BTech, Information Technology at Nagano National College of Technology Advanced Course
Stackoverflow
115reputation
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3questions
Github Skills (39)
ruby-rails10
pdf-document10
parser10
object-mapping10
type-check10
thread-safety10
testing10
rails10
wpgraphql10
mongodb-database10
ruby10
orm10
parsing10
wordpress-graphql10
parse10
Programming languages (23)
Github contributions (5)
rails/rails
Jun 2015 - Jun 2019
Ruby on Rails
Role in this project:
Backend Developer
Backend DeveloperContributions:31 commits, 39 PRs, 134 comments in 4 years 1 month
Contributions summary:Fumiaki primarily contributed to the Ruby on Rails framework, addressing various issues and enhancing existing functionalities. Their work included improving the `TimeWithZone#xmlschema` method, resolving an issue with autoloading nested classes/modules during marshaling, and removing dead constants from the `active_support` library. Additionally, the user focused on refining and improving existing tests within the Rails codebase. Several commits involved refactoring test-related code.
ruby-on-railsrailsframeworkrubymvc
ruby/rbs
Nov 2019 - Apr 2020
Type Signature for Ruby
Role in this project:Back-end Developer
Back-end DeveloperContributions:21 commits, 22 PRs, 17 comments in 5 months
Contributions summary:Fumiaki primarily contributed to the `rbs` repository, focusing on enhancing the type system for Ruby. Their work includes implementing support for new literal types like `kTRUE` and `kFALSE`, and extending the parser to recognize symbol literals such as `:$foo`, `@foo`, `:+`, and `-`. Furthermore, they added methods like `encode` and `encode!` to the `String` class, as well as support for `collect!` in `Array`. They also fixed CLI option handling.
railssignaturerubytype-checking
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