watatsumi

watatsumi is a SaaS platform built for boating license schools in Japan. It supports core school operations including online reservations, vessel management, staff scheduling, automated generation of government-required documents including mark sheets, and the complex calculations that Japan’s multi-tier boating license system demands. Launched in 2018, deployed across multiple schools, and still running in production today.

Japan’s boating license system is layered — license types, vessel tonnage, and navigation zones create a matrix of rules that determine which exams apply, which documents are required, and how fees are calculated. Most of this had been handled manually. Exam schedules and venue information were entered separately by each school, creating redundant work and error-prone data across the industry.

watatsumi integrates directly with official sources to pull exam schedules and venue data automatically. This reduced duplicate entry across businesses and removed a persistent source of manual errors from daily operations.

The interface was designed for staff who use it every day, not for a one-time impression. Complex operational workflows were mapped and simplified so common tasks could be completed with fewer decisions and less context switching. Feedback from staff at schools using the system has been consistently positive.

The system was built for an industry where many workflows were still handled manually, and it has been running in production for over seven years.

As the system behind reservations and document issuance for license schools, availability and data protection were primary requirements. The infrastructure was designed around stability, recoverability, and room to scale.

The application runs in Docker containers on AWS, with deployments automated from GitHub via Capistrano. An AWS WAF sits in front to block malicious traffic, while the database runs on RDS with managed backups and recovery options. Because the system handles personal information and official documents, availability and security were part of the architecture from the start. It has operated without major downtime since its 2018 launch.