Senior Fullstack Developer AI/GenAI/AI AGENT/LLM/RAG

Our client, a leading international Japanese IT solutions provider, is seeking an experienced Senior Fullstack Developer / Tech Lead specializing in AI & GenAI. In this role, you will take part in enterprise-grade software projects, developing, deploying, and maintaining AI-integrated Web and Mobile systems that optimize organizational management and business operations.

Key Responsibilities:

• Design, develop, and optimize features using Reactjs or Vuejs at the frontend.
• Develop backend using Python or Java.
• Research and deploy AI/LLM/GenAI solutions into products (Chatbot, AI Agent, RAG, Automation, AI Workflow...).
• Participate in requirement analysis and system architecture design.
• Optimize system performance, security, and scalability.
• Perform effort estimation, assign tasks, conduct code reviews, and mentor junior team members.
• Contribute to preparing technical proposals and solution recommendations for clients when required
• Work directly with clients/partners (when necessary).

Must Have:

• University or College degree in Computer Science, Software Engineering, Artificial Intelligence, or IT-related fields.
• Minimum 5 years of professional software engineering experience, including hands-on experience in system architecture design.
• Frontend Development: Practical experience building modern user interfaces using ReactJS or VueJS.
• Backend Development: Proficient in server-side development using Python (FastAPI, Django, Flask...), Java (Spring Boot...), or .NET.
• Database & Architecture: Solid experience in RESTful API design, database management (MySQL, PostgreSQL, MongoDB...), and cloud platforms (AWS, GCP, Azure) or Microservices architectures.
• DevOps Basics: Good working knowledge of Git, CI/CD pipelines, and Docker containerization.
• AI & GenAI Capabilities: Hands-on experience researching, developing, or integrating AI/GenAI solutions (LLMs, Chatbots, RAG, Prompt Engineering, AI Agents, and Workflow Automation).
• Soft Skills: Strong logical thinking, structured problem-solving skills, proactive responsibility, and effective team communication.
• Language Skill: Good ability to read and understand technical documentation in English.

Good to Have:

• Knowledge or experience working with Vector Databases (e.g., Pinecone, Weaviate, FAISS).
• Practical experience or background in Machine Learning and Deep Learning.
• Japanese language proficiency (JLPT N3 or above) or basic conversational English skills.
• Prior experience working directly with Japanese corporate clients or stakeholders.

Attractive Compensation & Financial Perks:

• Highly competitive base salary, periodically reviewed based on performance and contributions.
• Guaranteed 13th-month salary bonus plus attractive performance-based bonuses.
• 100% full gross salary paid directly during the 2-month probation period.
• Generous, fixed monthly Japanese language allowances for JLPT N2 / N1 holders.

Comprehensive Health & Well-being Coverage:

• Premium private healthcare insurance package (providing superior inpatient and outpatient coverage beyond standard public insurance).
• Comprehensive annual health checkups conducted at top-tier international clinics and medical centers.
• Full statutory social, health, and unemployment insurance contributions fully paid based on 100% of your real gross salary.

Modern Workspace & Healthy Work-Life Balance:

• High-performance, modern working devices (laptops, dual monitors, high-end accessories) fully equipped upon joining.
• Work-life balance is strictly prioritized with standard Monday-Friday working hours (no weekend work) and minimal overtime (OT compensated strictly according to Labor Law).
• Professional, transparent, and respectful workplace culture that combines Japanese precision with Vietnamese agility and open communication.

Career Development & Global Mobility:

• Direct opportunities to travel, train, or take on short-term/long-term onsite assignments in Japan.
• Structured career progression paths leading toward Solutions Architect, Technical Delivery Manager, or Project Management roles.
• Continuous internal/external training programs, tech talks, and full financial support for professional and language certifications.

Vibrant Company Culture & Team Bonding:

• Fully sponsored annual company trips at luxury 4-star/5-star resorts.
• Frequent team-building activities, departmental dinners, and festive celebrations (Mid-Autumn Festival, Christmas, Women's Day, Year-End Party).
• Dynamic employee clubs (football, badminton, running, board games) and regular engagement activities to foster strong team spirit.