English summary for screening — check the original posting before applying.
Develop and operate SaaS products like "SocialPlus", "Message Manager", and "CRM PLUS on LINE". This role focuses on the design and quality of backend systems handling LINE ID integration, authentication, customer data, and EC data, where design errors can significantly impact user experience.
Must-haves
- Experience in designing authentication/authorization systems (OpenID Connect / OAuth 2.0)
- Experience in backend development for systems handling large volumes of data and traffic
- Experience in improving and maintaining long-term Rails applications
- Experience in designing APIs for AI agents
- Experience in improving development team productivity
Nice-to-haves
- Experience with LINE login integration
- Experience with data consistency during account integration
- Experience with asynchronous processing (events, jobs)
- Experience with load control during high traffic
- Experience with Ruby/Rails/library updates
- Experience with DB performance optimization (N+1 queries, API latency)