Staff Machine Learning Engineer

Role and Responsibilities

• Set both technical and product direction, making the strategic bets across our LLM, agentic, and NLP systems while shaping how we design AI-driven experiences and set expectations with users.
• Design and build the distributed, agentic systems behind our products at company-wide scale: tool-using conversational agents, multi-turn context, retrieval-grounded reasoning, and the orchestration that ties them together.
• Turn massive, messy, real-world data into the trustworthy signal agents' reason over: entity recognition and linking, relation extraction, summarization, semantic search, and knowledge-graph generation.
• Build the evals and labeled-data flywheels that steer the work rather than gate it, turning "it feels better" into proof you can act on.
• Partner with and influence cross-functional teams to shape the technical roadmap, and drive issues to root cause when quality or operations are on the line.
• Raise the engineering bar with better patterns, better practices, and a standard other engineers want to match.

Relevant Skills And Experience

• BS, MS, or PhD in computer science, a related field, or equivalent practical experience.
• 6+ years building production backend software, with a track record of shipping and operating ML-driven functionality.
• Mastery of data structures and algorithms, and the judgment to translate user needs into practical solutions.
• Hands-on depth with LLMs and agentic systems (prompt and context engineering, tool use, retrieval and RAG) and the broader ML toolkit such as PyTorch, plus experience defining evals to measure and improve quality.
• Fluency authoring production APIs in Python (Rust a plus).
• High agency and a bias to action in ambiguous, fast-moving problems, plus the curiosity, generosity, and love of teaching that lifts a whole team.

Bonus Points

• Experience with knowledge graphs, information retrieval at scale, or LLM fine-tuning and post-training.
• A pull toward high-stakes, real-world problems where the work actually ships and someone depends on the answer.

What We Offer

• Competitive compensation and comprehensive benefits.
• Full medical, dental, and vision coverage.
• Fertility benefits through Carrot.
• Mental health coverage on demand with Headspace Care+.
• Gympass+ Membership via Wellhub.
• One Medical Membership.
• 401(k).
• Remote work stipends.
• Monthly internet allowance.

About the role

• We are a series D funded company with investors from Addition, USIT, Lux Capital, Amplify Partners, Addition Capital, Bloomberg Beta, and others.
• We are intentional around building a diverse and inclusive team of subject matter experts to better advocate for the needs of our users.
• We care a lot about our work and about the well being of our team.
• We encourage everyone to work at a sustainable pace and have a flexible vacation policy for team members to utilize, Wellness Days and 100% paid leave for parents of growing families.

Benefits

• Comprehensive benefits.
• Flexible vacation policy.
• Wellness Days.
• 100% paid leave for parents of growing families.

Schedule

• Remote work.

Pay

• Competitive compensation.

Company Information

• Primer has offices in San Francisco, Pasadena, CA, and Arlington, VA.
• For more information, please visit primer.ai.
• The company may rescind any offer of employment to an applicant or terminate an employee if the applicant or employee is unable to perform the functions of the position in compliance with applicable government contracts or if an applicant or employee makes a false attestation of compliance.
• We are an Equal Employment Opportunity and Affirmative Action employer.
• We do not discriminate based upon race, religion, color, national origin, gender (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, or other applicable legally protected characteristics.
• Pursuant to the San Francisco Fair Chance Ordinance, we will consider for employment qualified applicants with arrest and conviction records.