Full-Time

Staff AI Scientist

Posted on 5/7/2026

Fiddler AI

Fiddler AI

51-200 employees

Responsible AI platform for model monitoring

Compensation Overview

$175k - $260k/yr

+ Equity

Palo Alto, CA, USA

Hybrid

Must be in Palo Alto office 2-3 days per week.

Category
AI & Machine Learning (2)
,
Required Skills
LLM
Python
Pytorch
Machine Learning
Requirements
  • 7+ years of applied artificial intelligence experience, with a strong track record of taking models from research to production
  • Experience in large language models or agentic evaluations, guardrailing
  • Deep expertise training and fine-tuning classifier models, including modern encoder architectures (BERT-family, ModernBERT, etc.) and large language model-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 large language models and agentic systems – prompting, fine-tuning, and evaluation
  • Proficiency in Python and the modern machine learning 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 artificial intelligence 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, product managers, and customers
  • Ability to work in our Palo Alto office 2-3 days a week
Responsibilities
  • 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 to 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
Desired Qualifications
  • MS or Ph.D. in Computer Science, Machine Learning, Statistics, Physics, or a related quantitative field
  • Published research at top machine learning or natural language processing venues (NeurIPS, ICML, ICLR, ACL, EMNLP, etc.)
  • Experience with reinforcement learning, reinforcement learning from human feedback, reinforcement learning from AI feedback, or preference-based fine-tuning
  • Experience with synthetic data generation pipelines at scale
  • Background in artificial intelligence safety, red-teaming, or adversarial machine learning
  • Experience working with enterprise customers in regulated industries (finance, healthcare, government)

Fiddler AI provides a Responsible AI Platform for enterprises to build and maintain trustworthy AI. It offers a SaaS suite that helps data science and MLOps teams monitor, explain, validate, and analyze machine learning models in production. The platform works by aggregating model telemetry and applying governance, bias detection, explanations, and performance analytics to ensure models stay reliable and fair at scale. What sets Fiddler AI apart is its strong focus on AI observability, governance, and explainability across production models, helping organizations meet regulatory requirements and reduce risk. The company’s goal is to help customers deploy AI that is transparent, compliant, and trustworthy, improving performance and customer trust while managing risk.

Company Size

51-200

Company Stage

Series C

Total Funding

$93.8M

Headquarters

Palo Alto, California

Founded

2018

Simplify Jobs

Simplify's Take

What believers are saying

  • EU AI Act enforcement creates massive compliance demand for high-risk AI system monitoring.
  • 4x revenue growth in 18 months positions Fiddler as market leader in observability.
  • Series C funding enables expansion into healthcare, financial services, and insurance sectors.

What critics are saying

  • OpenAI's free built-in observability APIs for GPT models eliminate 70% of LLM monitoring revenue.
  • Arize AI's superior agentic tracing and RAG debugging erodes Fortune 500 customer base.
  • Honeycomb.io's open-source agent framework at 10x lower cost forces subscription price compression.

What makes Fiddler AI unique

  • Unified AI observability platform integrating model monitoring with data security via Lumeus acquisition.
  • Proprietary trust models and evaluations enable real-time governance for agentic AI systems.
  • Serves Fortune 500 organizations across regulated industries with compliance-focused control plane.

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Growth & Insights and Company News

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GetAIGovernance
Apr 10th, 2026
Fiddler AI acquires Lumeus AI to unify model monitoring and data security

Fiddler AI has acquired Lumeus AI, a cloud security startup specialising in data governance and zero-trust visibility, marking a shift towards unified AI observability and data security. The acquisition bridges the traditional gap between model performance monitoring and data privacy controls. Lumeus brings context-aware security that understands data sensitivity moving through AI pipelines. The combined platform will monitor both model health and data access simultaneously, enabling active governance features like automatic PII redaction and real-time access blocking. The move addresses growing enterprise pressures including shadow AI proliferation, regulatory demands, RAG complexity and data leakage incidents. By creating a unified control plane, Fiddler aims to automate compliance auditing and eliminate the friction between ML teams and security departments that has slowed AI deployment.

Business Wire
Feb 3rd, 2026
Fiddler Raises $30M Series C to Power the Control Plane for AI Agents

Fiddler AI, the enterprise AI observability and security platform, today announced it has raised $30 million in Series C funding led by RPS Ventures, with pa...

Fiddler AI
Feb 3rd, 2026
Announcing Series B and General Availability of Enterprise-Ready Fiddler | Fiddler AI Blog

Today, we’re excited to announce that enterprise-ready Fiddler is generally available, and we’ve raised $32 Million in Series B funding!

FinSMEs
Jan 27th, 2026
Fiddler AI Raises $30M in Series C Funding

Fiddler AI raises $30M in Series C funding. Fiddler AI, a Palo Alto, California-based provider of an enterprise AI observability and security platform, raised $30m in Series C funding. The round was led by RPS Ventures, with participation from existing investors Lightspeed Venture Partners, Lux Capital, Insight Partners, Capgemini Ventures, Dallas VC, Dentsu Ventures, and Mozilla Ventures, and new investors LG Technology Ventures, Benhamou Global Ventures, and LDV Partners. The company, which has secured $100m in total funding to date, intends to use the funds to expand operations and to scale its platform across regulated industries like healthcare, financial services, and insurance. Led by Co-founder and CEO Krishna Gade, Fiddler AI develops an all-in-one AI Control Plane that provides visibility, context, and control for AI agents, GenAI, and ML applications through proprietary trust models, evaluations, monitoring, and analytics capabilities. Its control plane for compound AI systems enables businesses to diagnose, explain, and govern their agentic decisions in real time. The company has grown its revenue more than 4x in the last 18 months, and achieved AWS Pattern Partners status. It serves Fortune 500 organizations.

Dallas Innovates
Dec 16th, 2024
Dallas Venture Capital Invests in Palo Alto-Based Fiddler AI's $50M Series B Round

Palo Alto, California-based Fiddler AI said its $18.6 million Series B extension brings the round's total funding to $50 million. The company said the funds will help it "continue to build momentum in AI observability and AI safety."