Lead Full Stack Engineer

Job Description

 Appealing Points:

• Lead cutting-edge, cloud-native engineering initiatives with end-to-end ownership across architecture, development, and deployment
• Work with modern technologies including AI/LLMs, Azure cloud services, and scalable microservices to build impactful enterprise solutions
• Mentor and influence a high-performing engineering team while driving innovation, best practices, and technical excellence

Annual Salary: 8 million yen and above

Job Description:

• 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 Company'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.

Job 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.

Job Qualification:

• 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.

Preferred Qualification:

• 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).

Nice to Have:

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

Language Proficiency: Conversational level Japanese (JLPT N3) and Business Level English

Company Description

Our Client has operations in more than 40 countries and holds leading market positions in the United States, Japan, Latin America, Asia, Europe, and the Middle East. We are ranked #43 on the Fortune 500 list for 2018. With over 150 years of experience, the companies offer life, accident and health insurance, retirement, and savings products through agents, third-party distributors such as banks and brokers, and direct marketing channels. Our name is recognized and trusted by approximately 100 million customers worldwide, and we serve more than 90 of the top 100 FORTUNE 500 companies in the United States.