Founder, BULL LLC | Creator of TenkaCloud

冨田進 / Susumu Tomita

Building hands-on cloud engineering systems. Founder of BULL LLC and creator of TenkaCloud, the open-source platform for running real AWS competitions.

TenkaCloud is an open-source, multi-tenant platform for running GameDay-style cloud competitions and hands-on training on real AWS accounts.Cloud Infrastructure, IaC, DevOps, Security, and Hands-on Engineering Education.

See TenkaCloud Contact GitHub

What I Build

TenkaCloud

Realistic cloud training breaks down when every event needs weeks of setup. TenkaCloud turns GameDay-style competitions into a repeatable platform: a multi-tenant control plane deploys challenge environments straight into participants' AWS accounts, so people learn on real infrastructure — not on slides or simulators.

Formats & platform

• Battle — real-time competitions between teams
• Challenge — self-paced problem solving on real AWS
• Operations console for organizers: tenants, roles, SSO, auditability
• Automated deploys into participants' own AWS accounts

Who it's for

• CCoE — Cloud Centers of Excellence running internal enablement
• SRE / Platform teams — Teams practicing incident response and operations
• Training managers — Technical training with real AWS accounts, not slides
• Universities & communities — Hands-on events without heavy per-event setup

The platform is open source. BULL LLC provides commercial support around it — hosting competitions, building custom problems, and adopting it in-house.

tenkacloud.com Source on GitHub Details & inquiries

Evidence

Verifiable track record

Not a self-introduction — each item links to a primary source: the conference platform, the organizer's page, or the published slides.

Selected Outcomes

Challenge → Action → Result

Challenge: Changes to an internal system took up to one month to reach production.
Action: Crossed into another department as an internal side job and introduced CI/CD and DevOps practices.
Result: Change lead time went from up to a month to ten minutes.

DevOpsDays Tokyo 2025 slides →

Challenge: Connected-car services needed cloud infrastructure that could be developed, operated, and monitored at scale.
Action: Designed and ran an AWS-native architecture for development, operations, and monitoring.
Result: Presented the architecture and operational practices at AWS DevDay Tokyo 2019.

AWS DevDay Tokyo 2019 slides →

Challenge: An operations team was stuck firefighting, down to “the login screen won’t open” tickets.
Action: Rebuilt the team's way of working with SRE practices.
Result: Shared the transformation journey at DevOpsDays Tokyo 2021.

DevOpsDays Tokyo 2021 session →

Challenge: Running realistic cloud competitions and hands-on training takes heavy preparation for every event.
Action: Built TenkaCloud, an open-source multi-tenant platform that deploys competition environments to participants' AWS accounts.
Result: The platform and its documentation are developed in the open on GitHub.

TenkaCloud on GitHub →

Selected Experience

Organizations I have worked with

Listed by relationship — employment and contract work, not customer endorsements. Details are on theAbout andResume pages.

As a full-time employee

Hitachi, Ltd. — QA engineer / technical lead (2006–2017)
Hitachi Vantara (US) — Software QA specialist (2017–2018)
DENSO — Software architect / cloud lead (2018–2025)

Under contract / side engagements

WHILL — Cloud application development (2021–2022)
Logomix — Lab automation / SRE (2025–2026)
MynaWallet — Web3 infrastructure and security (2025–)
DENSO — Agile coach (2026–)

Speaking & Writing

One consistent thread

Talks and writing revolve around the same themes: cloud infrastructure, IaC, DevOps, security, and organizational improvement.

Cloud infrastructure & IaC

AWS DevDay Tokyo 2019
HashiTalks: Japan

DevOps & organizational change

DevOpsDays Tokyo 2021 / 2025
DevOpsDays Taipei
Scrum Fest Mikawa 2023

Operations & security

Cloud Operator Days Tokyo 2022 / 2024

Slides on Speaker Deck Speaker profile on Sessionize Articles on Zenn

Speaking requests are welcome —get in touch.

2 books · 3 editions

Published Technical Books

Hands-on books built from working repositories, reproducible steps, and the same review discipline used for software.

How I write them →

Zig · Blockchain · EVM

Zig言語で学ぶブロックチェイン

Build a blockchain, P2P networking, chain synchronization, and a minimal EVM from scratch in Zig.

日本語版を読むZenn

AWS · GameDay · TenkaCloud

Build Your Own Cloud Competition

Design, build, and run GameDay-inspired AWS Challenges and Battles with TenkaCloud. Published in Japanese and English.

日本語版Zenn EnglishLeanpub

From QA to cloud, to building how engineers learn

I started in QA on mission-critical systems, moved into cloud architecture and SRE for connected services, and kept crossing team boundaries to fix how organizations deliver software. That thread — quality, infrastructure, and people learning by doing — is what led to founding BULL LLC and building TenkaCloud: education that runs on real AWS, not on slides.

Full background →

Contact

Pick the route that fits

Each route goes to the right form or page. I read every message and reply by email — no newsletters, no automated follow-ups.

General inquiries:inquiry form

冨田進 / Susumu Tomita