Platform Engineer

Senior Platform Engineer, Product Platform Development

¥9.5M – ¥15M JPY/year

Fully remote (Japan-based)

A fast-scaling cloud-based enterprise SaaS platform serving millions of users across multiple product lines. As we expand toward a multi-product ecosystem, we're building a dedicated Product Platform Team to own the shared foundations, integrations, and data flow across products. You'll design and operate the connective tissue that enables seamless experiences and deep synergies across our platform portfolio, from permissions and billing to event linkage and external-service data synchronization.

Environment & Tech Stack

• Multi-product SaaS architecture with shared platforms across domains
• Primary languages: Ruby on Rails 5.0 , full web-application stack
• Cloud infrastructure: GCP or AWS
• Development style: Scrum, one-week sprints, continuous design review
• AI-augmented dev workflows (GitHub Copilot, AI code assistants)
• Team: 6 engineers, 1 Product Manager, QA embedded

What We're Looking For

• 5 years hands-on web application development using a framework
• Data modeling, performance tuning, and production-scale system experience
• Proven team leadership in some form
• Interest in platform design, re-architecture of legacy/large-scale systems
• Business-level Japanese required; English nice-to-have

Ideal Candidate

• Thinks user-value-first, even for internal-facing features
• Embraces change and moves forward amid ambiguity
• Balances short-term product demands with long-term platform vision
• Supports psychological safety through constructive communication