Helps app, SaaS and AI businesses launch in Japan: market checks, localization, Japanese payments and PR, at fixed scope and price.
ken2618 / README.md
Hi, I'm Ken 馃憢
I help app, SaaS and AI companies launch in Japan through JapanReady, and I build Clarity.Do, a task manager for iPhone, Mac, Android and the web. Behind both are 28 years of building software, including more than 20 years working in Japan.
What I help with
- Is Japan worth it? Whether Japanese buyers want your product, and what stops them buying today.
- Japanese payments. PayPay, convenience-store payment, tax-inclusive yen pricing, and web checkout under Japan's new smartphone act.
- Localization that reads as Japanese. Across web, iOS, Android and desktop, not just translated.
- Selling to Japanese businesses. Quotes, invoices, bank transfer, security questionnaires and partners.
- Market entry, start to finish. Research, entry planning, launch and PR in Japanese.
- Software development. Web, mobile and desktop products built end to end, with AI-assisted development.
What I can advise on
- Japan market entry for software
- Japanese payments and fintech
- Front-office trading systems
- Retail banking and remittance
- Stablecoins and Web3 in Japan
- AI-assisted software development
- AI governance for engineering teams
- Engineering leadership and hiring
- Legacy system modernization
- Multi-platform app development
What I'm building
A task manager with a built-in priority matrix, focus mode and quick capture, synced across iPhone, Mac, Android and the web.
JapanReady and Clarity.Do are products of Clarity.Do LLC.
At a glance
- 28years building software
- 20+years working in Japan
- 15+years in financial systems
- 8+industries served
- 5platforms shipped
- 12programming languages
- 1M+users on systems built
- 10k+concurrent sessions handled
Experience
Japan market and payments
- Integrated PayPay, convenience-store payment, credit cards and other Japanese payment methods into production systems.
- Built B2B platforms for Japanese clients in real estate, automotive, staffing, finance, e-commerce and telecoms.
- Shipped Android RCS messaging across all three Japanese mobile carriers.
- Added full multi-language support across web, macOS, iOS, Android and Windows.
- Worked with international and Japanese companies of every size, from small businesses and startups to publicly listed corporations.
Financial systems
- Front-office FX and equities trading systems for a major Japanese securities firm and a megabank: real-time price distribution, order management, VWAP/TWAP execution, options valuation, basket trading and high-frequency modules.
- Distributed real-time Tokyo Stock Exchange market data at trading-floor throughput; trained traders in Hong Kong and London.
- Core development of a mobile and web retail banking platform for a bank outside Japan, in Java, Go, Rust, Swift and Kotlin.
- Program manager for payments and remittance systems; designed a chained transaction ledger that makes every gap and balance traceable.
- Architect and developer of a self-custody yen-stablecoin wallet for iOS and Android on Ethereum, Polygon and Arbitrum, plus NFT minting infrastructure in Solidity.
- Low-latency crypto market analytics on a Rust backend with an in-memory data store.
AI-native engineering
- Shipped a five-platform enterprise system (web, macOS, iOS, Android, Windows) solo in about 3 months with Claude Code: a scope budgeted at 3 developers for 6 months.
- Moved a 15+ engineer team to AI-assisted development under governance I designed: spec-first work, human-designed tests, CI guardrails, and clear permission and data boundaries for agents.
- Builds Claude-based agent pipelines on Rust with structured output, scoring and drafting, where a person approves every action.
- AI economics: token cost control, LLM ROI modelling and AI vendor negotiation.
Product building
- Designs, builds and ships Clarity.Do on iPhone, Mac, Android and the web.
- Native iOS (Swift), Android (Kotlin), macOS and Windows (C#) apps, plus Flutter and React Native.
- App Store Connect and Google Play release management.
- WebRTC video, chat apps, an Apple Watch-enabled CMS and IoT robotics control.
Scale and modernization
- Infrastructure supporting 1M+ users and 10,000+ concurrent sessions.
- Replaced a decade-old e-commerce codebase package by package, with the business running throughout.
- Ported Java and Python services to Rust: several-fold faster on substantially less CPU and memory.
- Built large-scale web systems in Silicon Valley, Seattle and Japan since 1998.
Leadership
- Led teams of up to 40 inside 100+ engineer organizations, reporting to client CEOs.
- Hired 100+ engineers, interviewed 1,000+, and grew individual contributors into tech leads.
- Designed release, QA and UAT processes, including a monthly release train that made delivery predictable.
- Bridges business and engineering: traders, executives and overseas partners.
Skills
Languages
Frontend
Mobile and desktop
Data
Cloud and infrastructure
AI
Payments and fintech
Engineering practice
Let's talk about Japan
Planning a Japan launch, or need an expert view on any of the topics above? Email is the fastest way to reach me.