AI Research Engineer

About Citadel AI

Citadel AI builds software products to evaluate, monitor, and govern AI systems. Our mission is to make the world’s AI systems more reliable and trustworthy.

We’re located in Tokyo, but we have an international team and global customers. Our goal is to build a world-class startup from Japan, and our team members have previously worked at leading companies such as Google, Paidy, Apple, Stripe, and Meta.

This is a unique opportunity to join a team in Tokyo building new products for a global market. As an early employee at Citadel AI, you’ll have significant impact and ownership over the growth of our startup. We’re supported by Japan’s best investors and a top-tier enterprise customer base, and are currently scaling our business in the 1 → 10 stage.

About the role

As an AI Research Engineer at Citadel AI, you will research technologies to ensure the safety and reliability of frontier AI systems, including frontier models, agent harnesses, and multi-agent and multi-modal systems. You will also study the broader impact these technologies may have on society and organizations. This role goes beyond literature reviews and field research: you will also design frameworks, build prototypes, and develop benchmarks.

Your work will not only be compiled into research reports, but may also be integrated into Citadel AI’s product portfolio. This is a key position for creating the foundation of our long-term technical differentiation. Compensation is a flexible combination of salary and stock options.

Responsibilities

• Conduct research on safety evaluation methods for frontier models, agent harnesses, multi-agent and multi-modal systems, and related technologies.
• Investigate risk assessment methods, attack methods, defense methods, and design and implement benchmarks.
• Participate in technical discussions and joint research with public institutions and major enterprises.
• Plan and execute R&D projects, and prepare evaluation reports.
• Propose ways to integrate your research into Citadel AI’s product portfolio.

Job requirements

• 2+ years of experience in research and development in generative AI or equivalent experience.
• Ability to investigate and analyze technical trends from research papers, including arXiv and conference publications, organize findings systematically, and document them clearly.
• Knowledge of LLMs, VLMs, and the AI ecosystem.
• Depending on the team, you must be fluent in either English or Japanese.

Nice to have

• Publications or presentations at major international conferences such as CVPR, ICML, or NeurIPS.
• Experience making technical proposals and delivering reports to clients in contract R&D projects.
• Experience building and operating AI agents.