Fullstack Engineer_Japan

Description and Requirements

About the Role

We are hiring a Lead Full Stack Engineer (Tech Lead) to provide hands-on technical leadership while building and operating modern, cloud-native applications aligned to MetLife’s standard engineering stack. This role drives end-to-end engineering execution across backend and frontend, with strong ownership of architecture, security, CI/CD, and reliability. You will collaborate closely with product and cross-functional stakeholders, mentor engineers, and guide technical decisions to deliver scalable solutions that integrate AI and Large Language Model (LLM) capabilities.

Key Responsibilities

• Provide technical leadership across the full software development lifecycle (design, build, test, deploy, and operate).
• Lead system and application architecture discussions; produce and maintain technical designs and diagrams.
• Build and maintain full stack applications using ReactJS and TypeScript on the frontend, and Java 17 + Spring Boot 3 on the backend.
• Architect and implement microservices and REST APIs with clean separation of concerns, scalability, and maintainability.
• Design and optimize data layers (SQL/NoSQL) including caching strategies and data modeling.
• Implement secure authentication and authorization using enterprise identity (e.g., Microsoft Entra ID) and token-based patterns (OAuth2/JWT) as applicable.
• Apply application and network security best practices (HTTPS, CORS, CSRF mitigation, rate limiting, private endpoints, firewall rules).
• Own CI/CD practices using Azure DevOps (pipelines, releases) and ensure required code quality and security scans are integrated.
• Build and deploy containerized workloads using Docker and run services on approved Azure hosting platforms such as Azure App Service and/or Azure Kubernetes Service (AKS).
• Use Azure-native services such as Azure Key Vault (secrets), Azure Blob Storage, Azure SQL Database, and Cosmos DB as applicable.
• Drive engineering best practices: code reviews, automated testing strategy, observability/monitoring, performance tuning, and documentation.
• Mentor and coach engineers; establish reusable patterns, standards, and reference implementations.
• Collaborate with cross-functional teams on feature planning, prioritization, and technical risk management.
• Train, fine-tune, or parameter-efficiently adapt AI/LLM models (e.g., LoRA/PEFT) to support product-specific use cases.

• 7+ years of professional experience in full stack development, including technical leadership responsibilities.
• Strong backend development and architecture skills with Java and Spring Boot (Spring Boot 3 preferred).
• Hands-on experience building backend services with .NET is a plus (for integration and modernization scenarios).
• Proficiency in ReactJS and TypeScript; understanding of UI/UX principles and responsive design.
• Experience with microservice architecture, RESTful APIs, and event-driven or asynchronous processing patterns.
• Solid system design fundamentals (data structures, distributed systems, performance).
• Experience with relational databases and one or more NoSQL databases; caching experience is a plus.
• Hands-on experience with Azure services commonly used for enterprise applications (e.g., App Service and/or AKS, Entra ID, Key Vault, Blob Storage, Azure SQL, Cosmos DB).
• CI/CD experience with Azure DevOps; strong repository management practices using Git.
• Strong understanding of networking fundamentals (DNS, load balancing, firewalls, VPNs).
• Clear communication skills and proven ability to collaborate across teams and stakeholders.

• Azure Monitor / Application Insights and log analytics for observability.
• Infrastructure as Code using approved Terraform templates/modules.
• API specifications and documentation using OpenAPI/Swagger.
• Experience with fine-tuning or customizing large language models or machine learning models using modern ML frameworks (PyTorch, TensorFlow).

• Japanese language proficiency.
• Experience working in agile teams and cross-cultural environments.
• Experience with enterprise dependency management and artifact repositories (e.g., JFrog/Artifactory).

MetLife Japan offers a comprehensive benefits package that promotes work-life balance and employee wellbeing. Employees can take advantage of flex time policy and a generous time-off policy, national holidays, annual paid leave, special consecutive leave, and refreshment leave. We also provide full social insurance coverage, a commuting expense reimbursement, group insurance, and discounts on travel and English language lessons. To support work flexibility, employees also have hybrid work options, shortened working hours for parents with children in third grade or below, and a casual dress code.

About MetLife

MetLife Inc., through its subsidiaries and affiliates (MetLife), is one of the world’s leading financial services companies, providing insurance, annuities, employee benefits and asset management to help individual and institutional customers build a more confident future. Founded in 1868, MetLife has operations in more than 40 markets globally and holds leading positions in the United States, Asia, Latin America, Europe and the Middle East.

MetLife Japan began operations in February 1973 as Japan’s first foreign-owned life insurance company. Our purpose, “Always with you, building a more confident future,” encapsulates our strong commitment to leveraging our global network and best practices worldwide to stand with our customers and build trust with our communities.