Job Description:

Rakuten International is a division of Rakuten Group, Inc., a Japanese global technology leader in services that empower individuals, communities, businesses and society. Headquartered in San Mateo, California with more than 4,000 employees worldwide, the Rakuten International business portfolio includes market leaders in e-commerce, digital marketing, advertising, communications and entertainment. We create products and services that provide exceptional value by aligning members and the businesses that want to engage them in a shared community.

About the Role:
Rakuten’s America AI & Data Division (AIDD) is seeking an Associate AI Engineer to join our innovative team at Rakuten. In your role, you will be dedicated to developing cutting-edge generative AI applications that transform customer service experiences. This role offers an opportunity to work on dynamic projects involving conversational AI orchestration, semantic knowledge retrieval, AI reasoning and action frameworks, retrieval evaluation, and automated testing – delivering meaningful impact for millions of users across the Rakuten platform.

You’ll join a team inspired by our CEO’s passion and strategic direction: “No AI, No Rakuten.” This mindset means that AI is not an optional extra—it’s at the heart of everything we do.

Key Responsibilities:

• AI Product Development
  • Design, build, and maintain AI-driven applications and services, covering both front-end and back-end development.
  • Collaborate with cross-functional teams to integrate AI features into customer-facing products.
• GenAI & Voice AI Integration
  • Develop and integrate AI frameworks using cutting-edge tools and SDKs (e.g., LangChain, LlamaIndex, OpenChat’s ChatCompletion, Agent SDK).
  • Experiment with speech-to-text (STT), text-to-speech (TTS), real-time transcription, and voice synthesis technologies to create next-gen conversational experiences.
  • Leverage LLMs and voice models to design natural, multimodal user interactions.
• API & Data Management
  • Build secure and scalable RESTful APIs and data pipelines for enterprise-grade AI workloads.
  • Work with relational and NoSQL databases to support real-time and batch AI applications.
• Testing & Optimization
  • Write unit and integration tests; debug, optimize, and ensure high system reliability and scalability.
• Collaboration & Continuous Learning
  • Work closely with product managers, UX designers, and engineers in the US, Japan, and globally.
  • Stay current on AI/LLM/Voice AI research and trends; propose and implement innovative ideas.

Qualifications:

• AI/GenAI:
  • Experience with Generative AI, LLMs (OpenAI, Google, open-source models, etc.), or frameworks like LangChain, LlamaIndex, or Agent SDK.
  • Academic or project experience in building, fine-tuning, or deploying LLMs.
• Voice & Voice AI (Strong Plus):
  • Familiarity with STT, TTS, or voice SDKs (e.g., Whisper, Deepgram, ElevenLabs, Google Speech, LiveKit, WebRTC).
  • Understanding of latency, streaming, and real-time system challenges for conversational AI.
• Mindset & Collaboration:
  • Ownership mentality with a bias for action and results.
  • Demonstrated ability to work in multicultural environments, including collaboration with Japanese teams.
  • Strong communication skills and openness to feedback.
• Other Plus Factors:
  • Contributions to open-source projects, Kaggle competitions, or AI hackathons.
  • Internship or project experience in conversational AI, customer service AI, or similar domains.

Minimum Requirements:

• Education: Bachelor’s or master’s degree in computer science, Computer Engineering, AI/ML, or a closely related field.
• Experience: AI-related internship with a global organization strongly preferred
• Programming Skills: Proficiency in Python, JavaScript/TypeScript, Java, or similar languages.
• Full-Stack Exposure: Familiarity with front-end frameworks (React, Angular, Vue) and back-end development.
• Database Knowledge: Hands-on experience with SQL and/or NoSQL databases.
• Cloud Exposure: Coursework, projects, or internship experience in cloud environments (AWS, GCP, or Azure).

Minimum Requirements:

• Education: Bachelor’s or master’s degree in computer science, Computer Engineering, AI/ML, or a closely related field.
• Experience: AI-related internship with a global organization strongly preferred
• Programming Skills: Proficiency in Python, JavaScript/TypeScript, Java, or similar languages.
• Full-Stack Exposure: Familiarity with front-end frameworks (React, Angular, Vue) and back-end development.
• Database Knowledge: Hands-on experience with SQL and/or NoSQL databases.
• Cloud Exposure: Coursework, projects, or internship experience in cloud environments (AWS, GCP, or Azure).

Five Principles for Success
Our worldwide practices describe specific behaviors that make Rakuten unique and united across the world. We expect Rakuten employees to model these 5 Shugi Principles of Success.

Always improve, Always Advance - Only be satisfied with complete success - Kaizen
Passionately Professional - Take an uncompromising approach to your work and be determined to be the best
Hypothesize - Practice - Validate – Shikumika - Use the Rakuten Cycle to succeed in unknown territory
Maximize Customer Satisfaction - The greatest satisfaction for our teams is seeing their customers smile
Speed!! Speed!! Speed!! - Always be conscious of time - take charge, set clear goals, and engage your team

At the time of posting, Rakuten expects the base compensation for this role to be within the range shown below. Individual compensation will vary based on job-related factors, including the skills, qualifications, and experience of the successful candidate as well as business need and geographic location. The successful applicant for this role will be eligible for discretionary bonus, health, vision, dental insurance, 401k matching, PTO, Volunteer Time Off (VTO), and other employee benefits as the company implements.