Staff AI Scientist

Job Title

Join a tight-knit, highly collaborative AI Science team that partners closely with some of the world's leading enterprise AI organizations.

What You'll Do:

• Lead applied research and development for the models and datasets at the core of Fiddler's Trust Service and suite of guardrail classifiers and evaluators that customers depend on to keep their LLM and agentic applications safe, accurate, and compliant in production.

• Partner closely with other engineering teams, Product, and Customer Success. You'll build strong relationships with customer data science and ML engineering teams, supporting their AI observability journey and ensuring they realize measurable value from Fiddler.

• Design, train, and ship production classifiers for safety, security, and quality detection (e.g., prompt injection, jailbreaks, PII, hallucination, faithfulness) under strict latency and cost constraints.

• Lead the development of synthetic and adversarial dataset pipelines, including novel methods for generating, filtering, and validating data that exposes failure modes our models need to learn.

• Drive the technical direction of generative insights – the LLM- and agent-powered analysis layer that helps customers diagnose what's going wrong in their AI applications and why.

• Contribute to the evaluation and experimentation infrastructure that lets the AI Science team and our customers reliably measure model quality, regression, and drift across rapidly evolving model populations.

• Explore reinforcement learning and preference-based methods where they offer real leverage over supervised baselines.

• Collaborate with Backend and Platform engineers to take research prototypes from notebook to a hardened, scaled, observable service.

• Partner with Product, Solutions Engineering, and Customer Success to translate enterprise customer needs into research problems and translate research results back into product.

• Mentor AI Scientists on the team, raise the technical bar through code review and design review, and represent Fiddler externally through publications, talks, or open-source contributions when appropriate.

What We're Looking For:

• 7+ years of applied AI experience, with a strong track record of taking models from research to production

• Experience in LLM or Agentic Evals, Guardrailing

• Deep expertise training and fine-tuning classifier models, including modern encoder architectures (BERT-family, ModernBERT, etc.) and LLM-as-classifier approaches; clear understanding of the tradeoffs between them

• Hands-on experience with dataset development as a first-class engineering discipline: sourcing, labeling, synthetic generation, adversarial augmentation, and quality control

• Strong applied experience with LLMs and agentic systems – prompting, fine-tuning, and evaluation

• Proficiency in Python and the modern ML stack (PyTorch, Hugging Face, common training/serving frameworks)

• Comfortable working in production environments and partnering with backend and platform engineers on real-time inference, monitoring, and rollout

• Excited by the prospect of using AI coding tools in your own workflow to push the limits of what one engineer can ship – responsibly, with a clear eye on quality, security, and the failure modes these tools introduce

• Excellent written and verbal communication; able to explain research tradeoffs to engineers, PMs, and customers

• Ability to work in our Palo Alto office 2-3 days a week

Even Better:

• M.S. or Ph.D. in Computer Science, Machine Learning, Statistics, Physics, or a related quantitative field

• Published research at top ML or NLP venues (NeurIPS, ICML, ICLR, ACL, EMNLP, etc.)

• Experience with reinforcement learning, RLHF, RLAIF, or preference-based fine-tuning

• Experience with synthetic data generation pipelines at scale

• Background in AI safety, red-teaming, or adversarial ML

• Experience working with enterprise customers in regulated industries (finance, healthcare, government)

Compensation:

For Bay Area, Seattle & New York City: $220,000 - $260,000 + equity & benefits

Other cities $175,000-$230,000 + equity & benefits

Benefits & Perks:

• Competitive pay + equity

• Premium health, dental & vision (100% premium coverage for employees)

• 401(k) plan

• Open PTO

• Monthly fitness reimbursement

• Paid parental leave

• Team and company events and offsites (this year was Las Vegas)

Palo Alto HQ Vibes

• Annual Caltrain pass

• Monthly in-office massages

• Fastrak reimbursement

• Lunch provided Mon–Thurs

• Happy hours and ping pong tournaments

• Fully stocked snacks and drinks

The posted range represents the expected salary range for this job requisition and does not include any other potential components of the compensation package and perks previously outlined. Ultimately, in determining pay, we'll consider your experience, leveling, location, and other job-related factors.

Fiddler is proud to be an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. If you require special accommodations in order to complete the interviews or perform job duties, please inform the recruiter at the beginning of the process.

Beware of job scam fraud. Our recruiters use @fiddler.ai email addresses exclusively. In the US, we do not conduct interviews via text or instant message, or ask for sensitive personal information such as bank account or social security numbers.