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Staff Ai Scientist

You’ll join a tight-knit, highly collaborative AI Science team that partners clo💼 Full-time🗓 2026-07-27

Core

Lead applied research and development for models and datasets powering Fiddler's Trust Service, guardrail classifiers, and evaluators to ensure LLM and agentic applications are safe, accurate, and compliant in production.

Role type

Staff AI Scientist (Applied Research & Production)

Builds

Production classifiers for safety/security/quality, synthetic/adversarial dataset pipelines, and LLM-powered diagnostic analysis layers.

Domain

Generative AI, AI Observability, Trust & Safety, LLM Guardrails

Deliverable

production ML models

Required skills

Applied AI research to production, LLM/Agentic evaluation and guardrails, classifier model training (BERT-family, LLM-as-classifier), dataset development (sourcing, labeling, synthetic generation, adversarial augmentation), Python, PyTorch, Hugging Face, real-time inference and monitoring, reinforcement learning and preference-based methods, technical mentorship

Preferred skills

Publications, talks, or open-source contributions

Technologies

PyTorch, Hugging Face, BERT-family, ModernBERT

Responsibilities

Lead applied R&D for core trust service models and guardrail classifiers; Design, train, and ship production classifiers under latency/cost constraints; Lead development of synthetic and adversarial dataset pipelines; Drive technical direction of generative insights (LLM/agent-powered analysis); Contribute to evaluation infrastructure for model quality and drift; Collaborate with backend engineers to scale research prototypes; Mentor AI Scientists and represent the team externally

Seniority

Staff, hands-on IC with mentorship and technical direction

Rewrite
## About the Role 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 ## About the Company At Fiddler, we understand the implications of AI and the impact that it has on human lives. Our company was born with the mission of building trust into AI. The rise of Generative AI and Agents has unlocked generalized intelligence but also widened the risk aperture and made it harder to ensure that AI applications are working well. Fiddler enables organizations to get ahead of these issues by helping deploy trustworthy, and transparent AI solutions. Fiddler partners with AI-first organizations to help build a long-term framework for responsible AI practices, which, in turn, builds trust with their user base. AI Engineers, Data Science, and business teams use Fiddler AI to monitor, evaluate, secure, analyze, and improve their AI solutions to drive better outcomes. Our platform enables engineering teams and business stakeholders alike to understand the "what", "why", and "how" behind AI outcomes. Fiddler AI is founded by Krishna Gade (engineering leader at Facebook, Pinterest, Twitter, and Microsoft) and Amit Paka (product leader at Microsoft, Samsung, Paypal and two-time founder). We are backed by Insight Partners, Lightspeed Venture Partners, and Lux Capital. Fiddler is recognized as a pioneer in the field of AI Observability and has received numerous accolades, including: 2022 a16z Data50 list, 2021 CB Insights AI 100 most promising startups, 2020 WEF Technology Pioneer, 2020 Forbes AI 50 most promising startups of 2020, and a 2019 Gartner Cool Vendor in Enterprise AI Governance and Ethical Response. By joining our brilliant (at least we think so) team, you will help pave the way in the AI Observability space. ## About the Team You'll join a tight-knit, highly collaborative AI Science team that partners closely with some of the world's leading enterprise AI organizations. We operate in a hybrid capacity, but stay deeply connected through constant communication, collaboration, and shared purpose. Our team thrives on knowledge sharing, peer learning, and collective problem solving – no one works in a silo. We celebrate each other's successes, support one another through complex challenges, and take pride in helping our customers achieve real-world impact with Fiddler's AI Observability platform. Every project is a team effort, and every win is shared. If you love working alongside smart, driven peers who genuinely care about both customer success and each other's growth, you'll feel right at home here. ## Why Join Us Our team is motivated to help build trust into AI to enable society harness the power of AI. Joining us means you get to make an impact by ensuring that AI applications at production scale across industries have operational transparency and security. We are an early-stage startup and have a rapidly growing team of intelligent and empathetic doers, thinkers, creators, builders, and everyone in between. The AI and ML industry has a rapid pace of innovation and the learning opportunities here are monumental. This is your chance to be a trailblazer.
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