Team
Who does the work, and how far the responsibility goes.
Design and technical decisions are made by the representative partner directly.
How we are set up
A two-person company: the representative partner holds technical responsibility, while the operating member handles engagement delivery and administration.
- Headcount
- 2
- Representative
- Shuji Iwata, Representative Partner
- Engagement types
- Consulting, architecture advisory, implementation, and operational support
Representative partner
Shuji Iwata
What the role covers
- •Architecture design optimized for long-term product evolution
- •Bridging business strategy and technical implementation
- •Building and operating cross-functional and global engineering teams
- •Driving AI adoption, process improvement, and product development through implementation
Languages
- TypeScript
- 9+ years
- Python
- 10+ years
- Rust
- 2+ years
- Go
- Production (2025)
- JavaScript / React
- 7+ years
Areas of depth
Frontend
React / Next.js / Vue / Tailwind CSS / Three.js / R3F / GSAP
Backend
Node.js / Flask / Express / Go (net/http)
Database
Prisma / TypeORM / SeaORM / PostgreSQL / SQLite / BigQuery
AI / ML
LangChain / LangSmith / SentenceTransformer / RAG systems / Dify / Prompt Engineering
Cloud
AWS (EC2, S3, Lambda)
Other
Docker / Linux / Git / CI/CD
A career spent between business and engineering
This is the personal career of our representative, Shuji Iwata. None of it was work of Rainpulse LLC.
Employed full-time at an operating company
Nov 2025 – Present
The employer and the work are not listed.
PocketSign Inc.
May 2025 – Jun 2025
Backend Engineer / Contract / Tokyo
- —Backend development for Layer 2 infrastructure in Go
- —Design and implementation of core backend services
CureApp / axianext
Jan 2023 – Oct 2025
Tech Lead / Contract / Independent / Remote
- —Led web development and service optimization for a healthcare AI platform
- —Built a ChatGPT-powered RAG Slackbot for internal knowledge management
- —Built AI services with LangChain, LangSmith, and SentenceTransformer
- —Formed and operated a three-person global engineering team
- —Frontend/backend optimization and UX improvement
Trishula LLC
Sep 2021 – Jan 2023
CTO / Executive / Tokyo
- —Led development of a Reddit-like meta-internet platform
- —Owned architecture, CI/CD, deployment, and team workflows
- —Managed a six-person engineering team
ClassDo Inc.
Sep 2020 – Sep 2021
Full-stack Engineer / Data Scientist / Full-time / Singapore / Fully remote
- —Developed an online education platform
- —Optimized canvas rendering and stroke interpolation algorithms
- —Improved the PDF output pipeline
- —Also served as Data Scientist
- —Worked in an English-speaking Singapore-based environment
Amazon Listing Automation System
Jun 2017 – Jun 2020
Full-stack Engineer / Contract / Tokyo
- —Designed and built an end-to-end product listing automation system
- —Browser automation, admin console, and data pipelines
- —Owned the full system architecture as the sole engineer
Payment Service "Staple"
Jan 2014 – Jun 2017
Frontend Engineer / Contract / Tokyo
- —Frontend development for a payment service
- —Implemented unit tests and admin console features
Open source
Open source and technical work
Ongoing technical work outside client engagements. Design decisions draw on what these implementations taught us.
root-paradigm
→Event-sourcing state system with PostgreSQL/SQLite, SSE, and MCP server
TypeScript
lay
→Minimal deep-lens state management library
TypeScript, React
darkcore
→Functor / Applicative / Monad abstractions for Python
Python
markdown-next
→Markdown parser with AST output and plugin system
TypeScript
rex
→Rx (Reactive Extensions) library for Nim
Nim
cray
→Workflow engine library
TypeScript