AI Engineer

Arceus•San Francisco, CA

2h•$180,000 - $260,000

About The Position

Arceus is building the AI-native law firm for the next generation of category-defining companies. We help fast-moving companies move contracts through legal at record speed, with transparency, predictable pricing, and top quality. We're hiring a Founding AI Engineer to build the intelligence at the core of our platform. You'll work directly with attorneys to encode real legal judgment into AI systems that get faster and more accurate over time.

Requirements

4+ years in software/ML engineering, with hands-on experience building LLM-powered or ML products in production
Strong grasp of applied LLM techniques: retrieval (RAG), evaluation, prompt and pipeline design, fine-tuning where appropriate
Track record of shipping AI features that perform reliably with real users and data
Strong software fundamentals and comfort owning systems end to end
Comfort with ambiguity and a fast-moving, high-ownership environment
Excellent judgment, communication, and a high bar for quality

Nice To Haves

experience in legal, fintech, or other domains where accuracy is high-stakes

Responsibilities

Design, build, and own the AI systems at the core of the platform: retrieval, extraction, generation, and the pipelines around them.
Build rigorous evaluation so we can measure and trust output quality, and improve it over time.
Partner directly with attorneys to translate review playbooks and judgment into AI systems that get better with use.
Work with software engineers to ship AI features reliably into production.
Stay close to the frontier and make sound calls on where to use which models, tools, and techniques.
Own accuracy and reliability — in this domain, quality is non-negotiable, and customer experience always comes first.