Gregorius Bryan

Senior Platform & Infrastructure Engineer

Tokyo, JP.

About

Trilingual Senior Platform & Infrastructure Engineer with a proven track record of accelerated promotion, specializing in the architecture of developer platforms and infrastructure at massive scale. Expertly resolved organizational deadlocks, unblocked global OS migrations for over 4,000 developers, and managed 60,000+ server fleets. Combines deep hands-on engineering expertise in Python ecosystem management and infrastructure automation with strong cross-cultural team leadership.

Work

Woven by Toyota

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Platform Engineer (Contract)

Tokyo, Tokyo, Japan

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Summary

Architected an organization-wide Python interpreter resolution policy for 4,000+ developers, decoupling Python from OS upgrade lifecycles to unblock global OS migrations with zero developer disruption.

Highlights

Architected and implemented a sane-default Python interpreter resolution layer for 4,000+ developers across heterogeneous monorepos (Bazel, Poetry, ad-hoc scripts).

Decoupled Python from OS upgrade lifecycles, successfully unblocking global OS migrations for a large developer base without disruption.

Rakuten Group, Inc.

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Senior Infrastructure Engineer

Tokyo, Tokyo, Japan

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Summary

Selected for merit-based promotion to Grade A (P4 / Senior Level) following a 2025 year-end performance review, recognized for leadership in hardware lab and decommissioning projects.

Highlights

Achieved merit-based promotion to Grade A (P4 / Senior Level) after demonstrating exceptional leadership in critical hardware lab and decommissioning initiatives.

Drove significant contributions to strategic infrastructure projects, leading to recognition in the 2025 year-end performance review.

Rakuten Group, Inc.

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Infrastructure Engineer

Tokyo, Tokyo, Japan

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Summary

Spearheaded the 0-to-1 development of an isolated hardware lab for pre-purchase benchmarking, taking full responsibility for architectural evolution, procurement, and automated testing.

Highlights

Spearheaded the 0-to-1 development of an isolated hardware lab for pre-purchase benchmarking, serving as Lead Designer and Owner for architectural evolution and automated testing.

Architected and implemented an end-to-end standardized server decommissioning workflow, adopted as the organizational standard, retiring 5,000+ legacy servers.

Achieved monthly savings of millions of yen by efficiently retiring 5,000+ legacy servers and mentored a successor to ensure long-term operational continuity.

Owned and maintained an internal automation framework repository (200k+ lines of Python/Config), performing root-cause analysis (RCA) on complex infrastructure failures to streamline global operations for multiple internal teams.

Rakuten Group, Inc.

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Associate Infrastructure Engineer

Tokyo, Tokyo, Japan

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Summary

Engineered and improved various automation pipelines for provisioning and configuration management of a 60,000+ server global Bare-Metal-as-a-Service (BMaaS) platform.

Highlights

Engineered and improved automation pipelines (Python, Bash, Jenkins) for provisioning and configuration management (Chef Infra) of a 60,000+ server global BMaaS platform.

Refactored the Python-based Chef cookbook delivery system, eliminating race conditions and non-deterministic behavior, reducing daily synchronization time by 12x (from 6h to 30m).

Reduced server provisioning errors from 30% to 10% by engineering automated firmware upgrades and hardware/network health-check workflows, significantly increasing deployment reliability.

Money Forward, Inc.

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Back-End Engineer (Internship)

Remote, Japan, Japan

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Summary

Implemented a circuit-breaker pattern in a Go microservice to enhance resilience and prevent cascading failures, ensuring service availability.

Highlights

Implemented a robust circuit-breaker pattern in a critical Go microservice, significantly enhancing system resilience and preventing cascading failures.

Contributed directly to improved service availability and stability by integrating advanced error handling mechanisms.

Volunteer

AI Program Teaching Assistant

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Kwansei Gakuin University

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Facilitated student mastery of API architecture and development environments for enhanced technical fluency.

Highlights

Mentored students in API architecture and development environments, significantly enhancing their technical fluency and problem-solving skills.

Provided hands-on support and guidance, contributing to improved comprehension and practical application of complex AI concepts.

Mathematics Instructor

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Kwansei Gakuin University

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Instructed a class of 30 international students, preparing them for university entrance exams.

Highlights

Instructed a class of 30 international students, successfully preparing them for rigorous university entrance examinations.

Developed and delivered comprehensive mathematics curriculum, leading to improved student performance and readiness for higher education.

Culture Festival Preparation Committee Member

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Kwansei Gakuin University

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Contributed to the planning and execution of the annual university culture festival.

Highlights

Collaborated with a team to plan and execute a successful university culture festival, enhancing campus community engagement.

Projection Mapping Club Member

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Kwansei Gakuin University

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Participated in the Projection Mapping Club, developing creative visual installations.

Highlights

Developed and implemented creative projection mapping installations, showcasing technical and artistic skills.

Education

Kwansei Gakuin University

Hyogo, Japan, Japan
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B.E. Computer Science and Engineering Grade: 3.88

Courses

Research Topic: Code-switching data generation for training Natural Language Processing models

Highest GPA in major

Awards

Alumni award for highest GPA in major

Kwansei Gakuin University

Recognized for achieving the highest GPA within the Computer Science and Engineering major.

Scholarship for highest GPA in academic year

Kwansei Gakuin University

Awarded for demonstrating exceptional academic performance with the highest GPA during the academic year.

Scholarship for Self-Supporting Students

Sato Yo International Scholarship Foundation (SISF)

Received a scholarship supporting self-supporting students based on academic merit and financial need.

Publications

The 20th Annual Workshop of the Australasian Language Technology Association

Australasian Language Technology Association

Presented research on 'Generating Code-Switched Text from Monolingual Text with Dependency Tree', contributing to advancements in Natural Language Processing.

Languages

Indonesian

English

Japanese

Certificates

AWS Certified Solutions Architect - Associate

Amazon Web Services (AWS)

Dante Certified Level 3

Audinate

Applied Information Technology Engineer Examination

IPA

TOEIC L&R Perfect Score (990 Points)

ETS

Fundamental Information Technology Engineer Examination

IPA

TOEFL iBT (108 Points)

ETS

Japanese-Language Proficiency Test N1

JEES

Skills

Systems & Infrastructure

Linux (RHEL/Debian), Bare-Metal-as-a-Service (BMaaS), Server Hardware & Lifecycle Management, On-premise Private Cloud.

Platform & DevOps

Bazel, Chef Infra, Ansible, Jenkins, GitHub Actions, Docker, Developer Tooling.

Programming Languages

Python, Bash, Go, Ruby, C++.

Competitive Programming

AtCoder, C++.

API Architecture

API Design, Development Environments.

Instruction & Mentorship

Technical Training, Curriculum Development, Student Support.