Chief of Staff Equity) at Mobius

Job Title

Chief of Staff

Not Disclosed + Equity

Mobius is a $5M pre-seed San Francisco startup building the critical infrastructure and high-quality reinforcement learning data required by frontier AI labs and enterprises.

As the Chief of Staff at Mobius, you will serve as the CEO's right hand in building a category-defining AI infrastructure company. You will bridge the gap between technical research and business operations, shaping product strategy and scaling internal systems. This founding-team role offers direct exposure to the forefront of LLM post-training and agentic RL.

San Francisco, USA

• Work directly with CEO Sijun, a UC Berkeley PhD specialist in agentic RL, at the intersection of AI research and infrastructure.
• Join a well-funded $5M pre-seed team solving the data bottleneck for the world's most advanced frontier AI labs and enterprises.
• Massive impact as a founding-team member with equity, helping build the company's operating systems and strategy from the ground up.

• Partner with the CEO on high-level research and product strategy to define the future of RL data curation.
• Own end-to-end business operations, managing day-to-day internal processes and coordinating between research teams and external partners.
• Build and implement scalable organizational systems that facilitate rapid growth and ensure seamless delivery to frontier AI clients.

• Proven experience as a versatile operator-strategist, ideally in a Chief of Staff, strategy consulting, or high-growth startup environment.
• Strong intellectual curiosity and the ability to engage deeply with a technical team focused on LLM post-training and agentic RL.
• Exceptional builder mindset with the ability to navigate early-stage ambiguity and take full ownership of company-wide internal functions.