Senior Fullstack AI Engineer
rakuten
Job Description
- AI Application Development: Build AI-powered chat applications, conversational interfaces, and intelligent user experiences
- Multi-Agent Systems: Design and implement complex AI workflows using, for example, LangGraph and multi-agentic architectures
- LLM Observability: Implement monitoring, logging, and performance tracking for AI/LLM integrations
- Frontend Development: Design, develop, and maintain responsive web applications using React, Next.js, and TypeScript with deep JavaScript expertise
- System Architecture: Make strategic technical decisions about AI application structure, data flow patterns, and scalability solutions
- Performance Engineering: Optimize Core Web Vitals, bundle analysis, rendering performance, and AI response times for complex applications
- API Integration: Develop and consume RESTful APIs, GraphQL services, and LLM APIs with proper error handling and state management
- Technical Leadership: Conduct code reviews, mentor junior developers, and establish frontend development standards
- Business Translation: Work with stakeholders to translate business requirements into technical solutions and feasibility assessments
- Test Automation: Develop comprehensive automated unit, integration, and end-to-end tests
- Production Support: Debug complex production issues, memory leaks, race conditions, and cross-browser inconsistencies
- Security Implementation: Implement authentication flows, XSS prevention, data privacy and AI safety measures
- Backend Development: Build and maintain Node.js/Express.js APIs, database integrations, and AI service orchestration
Requirements
Experience & Education
- Bachelor's degree in Computer Science, Engineering, or related field
- 5-8 years of experience in fullstack development with frontend focus
- Proven experience building chat applications and conversational interfaces
- Experience integrating with AI/ML APIs and LLM frameworks
- Strong analytical, problem-solving, and technical communication skills
- Excellent collaboration abilities and experience working in cross-functional teams
Core Technical Expertise
Frontend Technologies
- Advanced JavaScript (ES6+, closures, prototypes, async patterns, event loop, browser APIs)
- React.js with hooks, context, and modern patterns
- Next.js including SSR, SSG, and App Router
- TypeScript with deep understanding of type system
- Component libraries (Ant Design or Material-UI)
- State management solutions (Redux, React Query)
Backend & Data
- Node.js & Express.js for API development
- Database technologies (PostgreSQL, MongoDB, or MySQL)
- RESTful APIs and GraphQL services
AI/LLM Integration
- OpenAI APIs, LangChain, or similar frameworks
- Streaming AI responses and error handling
- Performance optimization for AI applications
- Multi-agent system implementation
Development Practices & Tools
- Modern testing frameworks (Jest, React Testing Library, Cypress)
- Performance monitoring and debugging tools
- Git version control and collaborative workflows
- CI/CD pipelines and deployment automation
- System architecture patterns and scalable application design
- Security best practices including authentication flows and XSS prevention
Performance & Optimization
- Core Web Vitals optimization
- Bundle analysis and rendering performance
- Memory management and browser-specific optimizations
- Cross-browser compatibility and debugging