Takashi Mima

Takashi Mima is a software engineer at Mercari, Inc and engages Web Security as a hobby.

Links

• GitHub (opens new window)
• LinkedIn (opens new window)
• X (opens new window)
• Qiita (opens new window)
• SpeakerDeck (opens new window)

Employments

• April 2023 - now
  Main Job: SWE at Mercari Inc.
  ID Platform Team / Go, Kubernetes

• February 2024 - now
  Side Job: SWE at GMO Flatt Security Inc.
  Shisho Cloud / Go, Kubernetes

Publication

• January 2025
  Practical Prototype Pollution (opens new window)
  SECCON Beginners 2025 in Kanazawa

• January 2025
  Deep Dive into embed Package in Go (opens new window)
  Gopher's Gathering

• September 2024
  GC24 Recap: Interface Internals (opens new window)
  mercari.go #27

• September 2024
  GopherCon 2024 Recap: Exploring the Go Compiler: Adding a "four" loop (opens new window)
  Go 1.23 Release Party & GopherCon 2024 Report

• May 2024
  OAuth 2.0 Dynamic Client Registration with Terraform Custom Provider in Unleash Mercari Tech! vol.3 (opens new window)
  TechBookFest vol.16

• November 2023
  Compiler Optimization of PGO in Go in Unleash Mercari Tech! vol.2 (opens new window)
  TechBookFest vol.15

• June 2023
  Knowledge by given implementation of logger for debug (opens new window)
  Go Conference 2023

Teaching and Mentoring

• December 2024
  Teacher in Web Category, SECCON Beginners in Okinawa.

• April 2024
  Teacher for Auth Platform Onboarding of DevDojo (opens new window).

• December 2023
  Mentor in Mercoin Hackathon (opens new window).

• July 2023
  Teacher for "Deep Dive into Vulnerabilities with Developing Vulnerability Scanner" (opens new window), Security Mini Camp in Mie.
  GitHub Repo for the class[JA] (opens new window)

• March 2023
  Teacher for Vulnerability Workshop in Aizu.

• September / October 2022
  Teacher in Web Category, SECCON Beginners in Sapporo / Fukuoka.

• August 2022
  AI Security Class Tutor, Security Camp 2022 Online.

• April 2021 - March 2022
  Research-Driven Course Assistant, SecHack365.

Awards / Honors

• GopherCon 2024 Challenge Series (opens new window) 2024
  Got 5 Individual Prizes: High Score! / Efficiency Expert / Prolific! / Under the Wire! / Master Spy!

• CTF for Connected Cars 2022
  2nd Place in CTF for Connected Cars as Team "docter_run"

• Geekten 2022
  SHAREVOX (opens new window)
  Grand Prize in AI/Data Analysis Category as Team "高度セキュリティ人材"

• PyTorch Annual Hackathon 2021
  prompt2slip (opens new window)
  2nd Place in PyTorch Responsible AI Development Tools & Libraries Category with alumnis of SecHack365

• Hardening 2020 H3DX
  1st Place as Team "おにぎりまみれ"

• Open Hack U 2020 Online Vol.5 (opens new window)
  1st Place as Team "さぼてんとゆかいな仲間たち"

Certifications

• April 2020 - March 2021
  SecHack365 Trainee in Research Driven Course
  Malgraph: Malware Detection System by Using Control Flow Graph. (opens new window)

• August 2019
  Security Camp(Vulnerability / Malware Analysis Course)

• June 2019
  Database Specialist Examination (DB)

• March 2019
  TOEIC 720

• June 2018
  Applied Information Technology Engineering Examination (AP)

• November 2017
  Fundermental Information Technology Engineering Examination (FE)

Internships

• December 2022 - January 2023
  Backend Engineer Internship at Mercari Inc.
  Partner Platform Team / Go, Python, Kubernetes

• February 2022
  Backend Engineering Internship at Recruit Holdings Co., Ltd.
  Hot Pepper Beauty Clinic, Improvement of the bff layer in Web Server / Java, Spring Boot

• October 2021 - December 2021
  Software Engineering Internship at Mercari Inc.
  ID Platform Team, Automation for OIDC Client Creation / Go, Terraform Custom Provider

• October 2021 - November 2021
  Software Engineering Internship at DeNA Inc.
  Go, GCP(Cloud Build, Cloud Run, Pub/Sub)

• September 2021 - October 2021
  Software Engineering Internship at Wantedly Inc.
  Recommendation Infrastructure Team / Go, Kubernetes

• August 2021 - September 2021
  Software Engineering Internship at Yahoo Japan Corporation.
  Advertising Distribution Team, Design-Development-Release-A/B Testing / C++, Java, Go

• July 2021 - August 2021
  Software Engineering Internship at Akatsuki Inc.
  Game Currency Infrastructure Development Team, API Design&Development and Performance Improvement / Go, GCP

• March 2021 - July 2021, December 2021 - March 2023
  Software Engineering Internship at 3-shake Inc.
  Go, GCP

• July 2020 - March 2021
  Software Engineer Internship at Mynavi Inc.
  Go, GCP(Cloud Build, Cloud Run)

Education

• April 2021 - March 2023
  Master's degree, Department of Electrical Engineering and Computer Science, Shibaura Institute of Technology, Japan.

• April 2017 - March 2021
  Bachelor's degree, Department of Computer Science and Engineering, Shibaura Institute of Technology, Japan.
  GPA 3.99/4.00

Skills

• Go(Intermediate)
  • dl - The logger not committed to Git for delog (opens new window)
  • OmnisCode(API) (opens new window)
  • taskctf21 (opens new window)
  • taskctf22 (opens new window)
• Python(Intermediate)
  • Malgrapher (opens new window)
  • SortFont (opens new window)
• C++(Intermediate)
  • For Competitive Programming
  • Solved Codes (opens new window)
• Java(Intermediate)
• PHP(Beginner)
  • Laravel
  • taskctf19 (opens new window)
  • taskctf20 (opens new window)
• Ruby(Beginner)
• JavaScript(Beginner)
• Rust(Beginner)
• Verilog(Beginner)