Job Description:

About Organization

The Architecture Review Board (ARB) acts as the final technical gatekeeper for every High-Level Design (HLD) within the Rakuten Mobile network. Our mission transcends basic technical feasibility; we analyze solutions through a multi-angle lens, including strategic necessity, security, infrastructure optimization, and competitive benchmarking.

We are currently spearheading two major initiatives:

• Tech SLM: A proprietary, AI-powered platform utilizing advanced LLM fine-tuning and high-precision RAG pipelines to automate design reviews and knowledge management.
• AI Council: A dedicated authority established to enforce audit frameworks, standardized design patterns, and cross-functional synergy for AI use cases across Rakuten Mobile. The ARB serves as a major stakeholder alongside Security and AIDD teams to ensure network stability and integrity.

Why Join Us

• Ultimate Tech Authority: Define blueprints, safety guidelines, and architectural guardrails for an entire cloud-native mobile network.
• Build Proprietary AI Assets: Go beyond basic APIs; fine-tune foundation models on massive, specialized telecom datasets.
• Solve RAG at Scale: Design high-precision, low-latency semantic search systems to eliminate hallucinations in complex network documentation.
• High-Impact Ownership: Prevent vendor lock-in and secure network stability while driving the transition toward an autonomous, AI-driven network.

Job Duties

• Tech SLM Engineering: Build the proprietary Tech SLM platform using advanced LLM fine-tuning and high-precision RAG pipelines to automate HLD creation and design reviews.
• Strategic AI Governance: Serve on the AI Council to validate use cases, set standardized design patterns, and enforce network-wide architectural guardrails.
• Algorithmic & Model Assessment: Evaluate open-source or proprietary models against strict telecom network performance, safety, and latency metrics.
• ML Infrastructure Review: Audit and review existing AI/ML infrastructure to provide design optimizations that streamline workloads and significantly reduce infrastructure usage.
• Vendor Auditing & Integration: Scrutinize third-party AI tools and agentic frameworks to ensure secure integration while preventing vendor lock-in.
• Architectural Guardrails: Define standardized architectural disciplines, design patterns, and best practices for AI/ML implementation across the network.
• Operational Integrity: Establish comprehensive monitoring frameworks to track model performance, safety, and data governance.
• Ecosystem Integration: Ensure seamless, secure, and low-latency integration of AI services within the existing Rakuten Mobile network stack.

Minimum Qualifications

• Bachelor’s degree in Computer Science, AI, Machine Learning, Data Science, Telecommunications Engineering, or a related field.
• 7+ years of total industry experience.
• 3+ years of experience in application/software design and architecture with AI/ML, including hands-on Generative AI implementation and model design.
• Strong expertise in LLMs/SLMs, fine-tuning techniques, RAG, vector databases, and prompt engineering.
• Experience designing and deploying scalable AI solutions using Python, cloud platforms, and Kubernetes.
• Solid understanding of AI governance, responsible AI practices, security, and data privacy.
• Basic understanding of Telco networks, Cloud, and networking technologies.
• Proficiency in English.

Preferred Qualifications

• Master’s degree in Computer Science, Data Science, or AI/ML fields.
• 7–15 years of total experience, with at least 3 years in AI/ML design and implementation.
• Experience in telecommunications, mobile network architecture, autonomous networks, and related AI use cases.
• Hands-on expertise with advanced LLM optimization (LoRA, QLoRA, model distillation) and agentic AI frameworks.
• Experience building enterprise AI platforms, AI copilots, or domain-specific language models.
• Strong knowledge of MLOps, AI observability, model monitoring, and lifecycle management tools.
• Proven ability to establish AI governance frameworks and assess third-party AI vendors.
• Relevant certifications (AWS, Azure, GCP, NVIDIA, or equivalent).
• Japanese language skills are an additional advantage.

Languages: