# Lead AI Engineer

**Company:** [Sphere](https://hotfix.jobs/companies/sphere)
**Location:** San Francisco, CA
**Role:** ML Engineering
**Salary:** $250k – $280k/yr
**Skills:** RAG, LLMs, Fine-Tuning, Retrieval Pipelines, Evaluation Frameworks, Data Pipelines, Reasoning Models
**Posted:** 2025-10-07

> Leads development of proprietary AI reasoning model TRAM for interpreting global trade law, building data pipelines, fine-tuning LLMs, and evaluation frameworks for high-speed, accurate compliance determinations. Requires AI product experience, especially RAG systems and model fine-tuning.

## Job Description

## What You'll Do

### Within weeks:
- Lead development of new features aimed at increasing TRAM’s test-time accuracy
- Work on the underlying data and retrieval pipelines that help power our AI workflows
- Work directly with our internal tax experts to understand how TRAM can better reason like them

### Within months:
- Own TRAM’s eval framework and workflows
- Work directly with leading frontier labs to reinforce fine tune models on our proprietary data

## Requirements
- Prior experience building AI enabled products, particularly **RAG systems**
- Experience fine tuning base models, ideally via **RF**
- Willingness to dive into tax technical problems
- A strong understanding of how **LLMs** and reasoning models function

## Nice to Haves
- Experience working with **LLMs** on legal applications
- Experience with **RAG data pipelines** and collecting/curating data for the pipeline

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