Backend Engineer, Identity Authentication Platform

This role develops and operates WealthNavi ID, a shared authentication platform for multiple financial services including asset management, insurance, securities trading, and digital banking. The ID platform is intended to provide secure, seamless access across services and support customer data connections across products.

As a core member of the dedicated ID platform team established in July 2026, the engineer will extend, maintain, and operate the common platform. Responsibilities include feature development and performance improvements using Auth0 and Java/Spring Boot; designing ID and data integration architectures with surrounding services and external systems; and implementing APIs. The role also develops and improves the user experience for secure registration, login, and MFA during system integration. It includes identifying development and operations bottlenecks, proposing and implementing refactoring and other improvements, and taking responsibility for operations after release.

The engineer will participate in large-scale integration with Mitsubishi UFJ eSmart Securities and projects related to a new digital bank. The work involves building an authentication foundation that can support high traffic, large-scale system and data integration, strong security, and newer authentication technologies such as passkeys. Requirements and specifications must be analyzed independently, with solutions carried through to implementation in cooperation with lead engineers and engineering managers.

Required qualifications include practical experience in server-side development using Java and Spring Boot, approximately three years or more, an interest in authentication and authorization areas such as OAuth 2.0 and OIDC, and the ability to analyze requirements and specifications and work independently through completion on complex large-scale integration projects. Experience with Auth0, AWS infrastructure, ECS, Aurora, DynamoDB, NoSQL, TypeScript, or React is welcome, as are experience with requirements definition, documenting undocumented systems, legacy modernization, or rearchitecting existing systems.

The environment includes Auth0, Java/Spring Boot, TypeScript, Node.js, React, AWS, ECS, Datadog, Aurora with MySQL, DynamoDB, GitHub, Slack, Notion, Google Docs, Gemini, GitHub Copilot, and Claude Code.

This is a full-time permanent position in Shinagawa, Tokyo, with an annual salary of ¥6,000,000–¥11,500,000 paid in 12 monthly installments. Working hours use a flextime system with core hours from 10:00 to 16:00 and a 60-minute break. The position uses hybrid work with at least three days per week in the office and the remainder at home, subject to assignment-specific exceptions. Holidays include Saturdays, Sundays, public holidays, year-end and New Year holidays, and other company-designated leave. Social insurance, commuting allowance for direct employees, defined-contribution pension, learning subsidies, health-related benefits, and optional Mac or Windows computers are provided as stated in the posting.