Krishna Gade raises $30M Series C for Fiddler AI - Jan 2026 Fiddler AI acquires Lumeus.ai to build AI Agent Control Plane $112M+ total funding for the AI trust layer powering Fortune 500s Former Facebook engineering manager who built "Why am I seeing this?" Serving US Navy, Fortune 500s and regulated industries worldwide Backed by In-Q-Tel, Lockheed Martin, Mozilla, Cisco, Amazon Alexa Fund Pioneer of AI observability before it had a name Krishna Gade raises $30M Series C for Fiddler AI - Jan 2026 Fiddler AI acquires Lumeus.ai to build AI Agent Control Plane $112M+ total funding for the AI trust layer powering Fortune 500s Former Facebook engineering manager who built "Why am I seeing this?" Serving US Navy, Fortune 500s and regulated industries worldwide Backed by In-Q-Tel, Lockheed Martin, Mozilla, Cisco, Amazon Alexa Fund Pioneer of AI observability before it had a name
Krishna Gade, Founder & CEO of Fiddler AI
YesPress Profile • Founder • AI / Enterprise

Krishna
Gade

Co-Founder & CEO — Fiddler AI • Palo Alto, CA

He spent 20 years building the infrastructure that powers the internet's most consequential algorithms. Then he built a company to hold them accountable.

AI Observability Explainable AI $112M+ Raised Series C Former Facebook / Pinterest / Twitter
$112M+
Total funding raised across Seed through Series C
20 yrs
Building data and ML infrastructure at internet scale
4
Big tech stops before founding Fiddler: Microsoft, Twitter, Pinterest, Facebook
Billions
Users affected by "Why am I seeing this?" - the feature he built at Facebook

The Audit Trail

In 2017, Facebook's News Feed was under fire. Billions of posts, ranked by algorithms nobody could see, shaping what a billion people believed. Krishna Gade was the engineering manager whose team got handed the hardest question in tech: how do you explain a machine's decision to a human being?

The result was "Why am I seeing this?" - a small button that opened a window into the black box of algorithmic recommendation. For the first time, at scale, users could ask a platform why it thought they needed to see a particular post. Gade's team had built the industry's first large-scale AI explainability feature, deployed to billions.

He spent a year sitting with what that meant. Teams at every company were deploying AI with no idea what their models were actually doing. The decisions those models made - who gets a loan, which resume gets flagged, what news travels - had real consequences. And nobody was watching.

I realized that teams were investing heavily in AI without having a clear understanding of the decisions their models were making.

- Krishna Gade, on founding Fiddler AI

In October 2018, Gade left Facebook and co-founded Fiddler Labs - alongside Amit Paka and Manoj Cheenath - in Palo Alto. The original pitch was almost humble: a "Tableau-like tool for machine learning," something that would make model behavior as visible as a bar chart. Lightspeed Venture Partners and Bloomberg Beta wrote the first check in a $3 million seed round. They had seen something.

What they had seen was a category waiting to be named. Fiddler called it AI Observability. Model monitoring, explainability, bias detection, fairness assessment - assembled into a platform that sits between an enterprise's AI and the consequences of its decisions. The US Navy signed on. Fortune 500 banks and insurance companies followed. The CIA's venture arm, In-Q-Tel, invested.

By January 2026, Fiddler had raised $30 million in a Series C led by RPS Ventures, bringing total funding past $112 million. The question Gade's team answered at Facebook had become a $100-million-plus enterprise business - and with AI agents now making decisions that no single human ever reviews, he argues the problem is only getting bigger.


Infrastructure First

Gade came to the US from India to study computer science at the University of Minnesota, finishing his MS in 2004 with research focused on document clustering - a quiet foreshadowing of a career spent wrangling information at scale.

He joined Microsoft, where he spent five years on the Bing Search Engine - building index quality measurement systems, static rank infrastructure, web spam detection, and query suggestions. The web in 2004 was still mostly a document retrieval problem. Gade was solving it at Microsoft's scale.

Twitter came next. In the early 2010s, when social media was transforming what "real-time" meant for information systems, Gade led the web search and real-time search engineering teams. He built streaming data infrastructure using Apache Storm - one of the early production deployments of stream processing at that scale. His systems tracked the news as it happened.

Microsoft / Bing
Software Development Engineer
2004 - 2009
Twitter
Engineering Leader, Search
2010 - 2013
Pinterest
Head of Data Engineering
2013 - 2016
Facebook
Engineering Manager, News Feed
2016 - 2018
Fiddler AI
Co-Founder & CEO
2018 - Present

Pinterest was where Gade learned to build teams as much as systems. He joined as a two-person data engineering function and grew it to 25+ engineers. He built the A/B testing framework, the scalable logging pipeline, fast interactive query infrastructure, and self-service batch processing that handled hundreds of petabytes. Pinterest's data team became a model for how data infrastructure gets done at a fast-growing consumer platform.

Then Facebook, and the News Feed ranking problem. Gade ran the engineering team responsible for understanding why the most-read content feed in history surfaced what it surfaced. "Why am I seeing this?" was not a regulatory box to check. It was, for Gade's team, the answer to a genuine engineering question: can you make the algorithm legible?

Unless we foster transparency, fairness, and accountability, in this new decade we can't ensure Algorithmic Justice for all.

- Krishna Gade

The answer was yes - but it required a new kind of infrastructure. Infrastructure for observability. Infrastructure for accountability. That was Fiddler.


Fiddler AI: The Trust Layer

Fiddler AI is not in the business of building AI models. It is in the business of watching them. The platform sits in production between a company's AI system and the decisions it produces - monitoring for model drift, detecting bias, surfacing explainability, tracking data distribution shifts, and generating audit trails for regulators.

The original use case was predictive models in finance and insurance - high-stakes decisions where a wrong prediction meant a loan denial or a claims refusal, and where regulators increasingly wanted to know why. Fiddler gave risk teams the ability to see which features drove a model's output, when those features started shifting, and where fairness metrics were degrading.

$112M+
Total Funding Raised
Series C
Latest Funding Round (Jan 2026)
110+
Employees
Fortune 500
Enterprise Customer Base

The platform evolved as the AI landscape did. When large language models moved from research to production, Fiddler expanded into LLM observability - monitoring hallucination rates, input/output quality, guardrails for sensitive content, and latency across multi-model chains. The product today covers the full lifecycle: from predictive models to generative AI to agentic systems.

Funding History

Seed
$3M
Lightspeed, Bloomberg Beta, Haystack
Series A
$10.2M
Series B
$50M
Insight Partners, Lockheed Martin, Amazon Alexa Fund, In-Q-Tel, Cisco, Mozilla
Series C
$30M
RPS Ventures, Lightspeed, Lux Capital, Capgemini Ventures, Mozilla, LG Technology

In 2025, Fiddler acquired Lumeus.ai to extend its reach into AI agents - systems that autonomously browse, execute code, call APIs, and make sequential decisions. Gade has been direct about the concern: "There's a growing gap where organisations lack control over the behaviour of these agents" - where agents produce insecure code, expose sensitive data, misuse tools, or execute unintended workflows at scale. The acquisition gives Fiddler observability at both the creation layer and the runtime layer of agentic AI systems.

Why It Matters

The US intelligence community invested in Fiddler through In-Q-Tel. When the CIA's venture arm backs an AI monitoring startup, the national security case for AI accountability is no longer theoretical.


Algorithmic Justice

Gade has a phrase he returns to: "Algorithmic Justice." It is not marketing copy. It is his argument that every system making decisions that affect humans - hiring, lending, healthcare, content - has an obligation to be auditable, and that building the tools to make that auditing possible is itself a form of justice work.

The argument is grounded in specifics. Bias in lending models has measurable disparate impact on protected classes. Data drift in healthcare models means a classifier trained on one patient population quietly degrades when deployed to another. Hallucinating LLMs in customer service applications put companies at legal risk while confusing real people. These are not hypotheticals - they are production incidents that Fiddler's customers are trying to prevent.

Humans are responsible for decisions made by machines, and it's our responsibility to make sure algorithms are maintained, supported, and monitored.

- Krishna Gade

The platform reflects the philosophy. Fiddler does not just alert when a model underperforms - it provides root cause analysis. It does not just flag potential bias - it quantifies fairness metrics across demographic attributes and explains which input features are driving the disparity. It does not just monitor LLM outputs - it offers guardrails that intercept unsafe or off-topic responses before they reach users.

The "four pillars" Gade describes for model performance management - monitoring, root cause analytics, explainability, and fairness - are not a product brochure. They are a framework for what responsible deployment actually requires. Building a model is no longer enough. Watching it is the job that comes after.


Milestones

2004
Completes MS in Computer Science at University of Minnesota; joins Microsoft to build Bing search infrastructure
2010
Joins Twitter as engineering leader for web search and real-time search; builds Apache Storm streaming infrastructure
2013
Joins Pinterest as Head of Data Engineering; scales team from 2 to 25+ engineers; builds petabyte-scale analytics infrastructure
2016
Joins Facebook as Engineering Manager on News Feed Ranking Platform
2017
Leads team that ships "Why am I seeing this?" - the first large-scale AI explainability feature deployed to a global audience
Oct 2018
Co-founds Fiddler Labs with Amit Paka and Manoj Cheenath; raises $3M seed from Lightspeed, Bloomberg Beta, Haystack
2020
Closes $10.2M Series A; platform expands beyond explainability to model monitoring
2021
Raises $32M Series B with Lockheed Martin, Amazon Alexa Fund, and In-Q-Tel as strategic investors
2022
Launches giga-scale model performance management; speaks at Amazon re:MARS in Las Vegas
2024
Series B extension closes at $18.6M with Cisco Investments, Samsung NEXT, Mozilla Ventures; expands to LLM observability
2025
Acquires Lumeus.ai to build AI Control Plane for agentic AI systems
Jan 2026
Raises $30M Series C led by RPS Ventures; total funding exceeds $112M; positions Fiddler as control plane for the AI agent economy

What He Built

  • Led creation of "Why am I seeing this?" at Facebook - the first high-scale AI explainability feature deployed to billions of users
  • Co-founded Fiddler AI, raising over $112 million across five funding rounds from Seed through Series C
  • Attracted strategic investment from Lockheed Martin, Amazon Alexa Fund, In-Q-Tel (CIA), Mozilla Ventures, and Cisco Investments
  • Scaled Pinterest's data engineering team from 2 to 25+ engineers while building petabyte-scale infrastructure
  • Built Twitter's real-time search and streaming data infrastructure at one of the earliest production deployments of Apache Storm
  • First company to offer a unified AI Control Plane at both agent creation layer and runtime layer
  • Fiddler AI now serves Fortune 500 enterprises and US government agencies including the US Navy
  • Pioneer of the AI observability category before the category had a name
  • Speaker at Amazon re:MARS, NYSE Floor Talk, Montgomery Summit, MachineCon, TWIMLcon, and O'Reilly Strata

On Video

Gade speaks with infrastructure clarity and startup urgency. These conversations span his views on AI accountability, model governance, and the emerging challenge of agentic AI systems.


The Vocabulary He Works In

AI Observability ML Monitoring Explainable AI Model Drift Bias Detection LLM Guardrails AI Governance Responsible AI MLOps LLMOps AI Safety Algorithmic Justice Agentic AI Model Explainability Fairness in AI Data Drift Root Cause Analysis AI Compliance Real-time Monitoring Enterprise AI AI Transparency Generative AI NLP Monitoring Multi-Agent Systems
On Building Trust in AI
"Our mission is to build trust into AI. Transparency and security are the foundations of trust, and we embed them into every aspect of the platform."
Krishna Gade - Co-Founder & CEO, Fiddler AI
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