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Founding LLM Engineer

Spherecast

Spherecast

Software Engineering, Data Science
San Francisco, CA, USA
USD 110k-200k / year
Posted on Feb 4, 2026

Spherecast

AI Supply Chain Manager for CPG

Founding LLM Engineer

$110K - $200KSan Francisco, CA, US
Job type
Full-time
Role
Engineering, Backend
Experience
1+ years
Visa
Will sponsor
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Leon Hergert
Founder
Leon Hergert
Founder

About the role

Founding LLM Engineer – Agnes

As a LLM Engineer at Spherecast, you will be responsible for building Agnes from the ground up – our AI Supply Chain Manager that decides what to produce, where to make it, and how to move it through factories, warehouses, and channels.

This is a fast-paced, highly autonomous role for someone who can own AI systems end-to-end: from prototypes to production, from prompts to tested and evaluated pipelines, from agents to real-world outcomes (POs, TOs, bookings). You’ll work directly with the core team to turn the physical flow of goods into something as programmable as code.

If you’re a builder who thrives at the intersection of LLMs, agents, systems engineering, and messy real-world data, this is your opportunity to shape how global brands run their supply chains.

What we’re looking for

You are a great fit if you have:

  • Hands-on experience with modern LLM APIs (e.g. Anthropic, OpenAI, DeepSeek, OpenRouter, Gemini, Moonshot) and have shipped features using them.
  • Strong intuition for large language model selection – you understand the strengths, weaknesses, latency/cost tradeoffs, and ideal use cases of different LLMs.
  • Practical experience with the HuggingFace ecosystem in real projects.
  • A track record of building LLM-powered automations or agents that are core to a production system, not just internal demos or playgrounds.
  • Experience designing and maintaining evaluation pipelines to iterate quickly and safely on prompts and workflows.
  • Strong prompting and system-design skills – you know how to design tools/functions, structured outputs, and multi-step agent flows that are robust to edge cases.
  • Experience with LLM observability and monitoring (logging, traces, quality metrics, feedback loops) to track and improve production accuracy over time.
  • Bonus: Experience running self-hosted LLMs in production or serious prototypes.

About Spherecast

Spherecast is building Agnes, the AI Supply Chain Manager for Consumer Goods.

Agnes decides what to produce, where to make it, and how to move it through factories, warehouses, and channels – simulating thousands of options in seconds and executing the best plan.

We are building Agnes to shape the physical flow of goods in the world, turning it into something as programmable as code.

When we succeed, every consumer product you touch will run on the Spherecast stack – planned in the Spherecast OS, executed over Spherecast Rails, and optimized by the shared Spherecast Network.

Oracle turned atoms into bits. Spherecast turns bits back to atoms, but globally optimized.

Be part of the next $T company.