Kota Mizushima
Software Expert at Walc Inc.
Tokyo, Japan
Summary
👤
Senior🎓
Top SchoolKota Mizushima is a software expert based in Tokyo with 16 years of experience bridging academia and industry, holding a Ph.D. in engineering from the University of Tsukuba. He brings deep expertise in Java, Scala, Ruby, and programming languages and formal language theory, with practical focus on compilers and parsers. Kota has contributed to high-profile open-source Scala projects—improving compiler test suites and building a widely used Scala wrapper for Joda Time—demonstrating a strong emphasis on test-driven quality and maintainability. His career spans roles from hands-on backend development to technology evangelism, reflecting both research rigor and product-minded engineering. Colleagues describe him as someone who pairs formal CS foundations with pragmatic tooling improvements that reduce real-world friction for developers.
16 years of coding experience
10 years of employment as a software developer
Ph. D, Computer Science, Ph. D, Computer Science at 筑波大学 / University of Tsukuba
Stackoverflow
601reputation
9kreached
5answers
1question
Github Skills (18)
datetime10
testing10
datetimes10
scala10
scala-compiler10
joda-time10
implicit9
implicits9
functional-programming8
jvm-languages7
type-conversion6
scala-collections6
generics6
android6
kotlin6
Programming languages (14)
Github contributions (5)
nscala-time/nscala-time
Dec 2012 - Apr 2018
A new Scala wrapper for Joda Time based on scala-time
Role in this project:
Back-end Developer
Back-end DeveloperContributions:125 commits, 13 PRs, 20 pushes in 5 years 5 months
Contributions summary:Kota primarily focused on creating a Scala wrapper for Joda Time, as indicated by the initial commit that created the project based on existing source code. The user then implemented the core functionality by defining numerous rich types for various Joda Time classes (e.g., `RichDateTime`, `RichLocalDate`). Their contributions included adapting the project to utilize pimped types and restructuring the package names and dependencies to improve the project's build and structure.
datetimejoda-timescalajsscala-wrapperscala3
scala/scala
Jan 2012 - Jun 2019
Scala 2 compiler and standard library. Scala 2 bugs at https://github.com/scala/bug; Scala 3 at https://github.com/scala/scala3
Role in this project:QA Engineer / Test Automation Engineer
QA Engineer / Test Automation EngineerContributions:8 commits, 4 PRs, 20 comments in 7 years 6 months
Contributions summary:Kota primarily contributed to the test suite of the Scala compiler and standard library. Their work involved adding new test cases to verify bug fixes, specifically for issues like SI-5377 and SI-4835. They also addressed a test failure related to non-English environments and added type annotations. These contributions indicate a focus on ensuring code quality and maintainability through rigorous testing.
functional-programmingobject-oriented-programmingscala-libraryscala-programming-languagestandard-library
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