AI Researcher & Engineering Leader

Dr. Siddhartha Reddy
Jonnalagadda

Principal Machine Learning Engineer at Pinterest. Previously built AI systems at Meta (AI Glasses), Google (Gemini, NotebookLM), Amazon (Alexa), Microsoft (Cortana), and Conversica. Former faculty at Northwestern, UC Berkeley, and Mayo Clinic. 120+ publications and patents in LLMs, deep learning, and NLP.

Two Decades of Building AI

From academic NLP research to the models behind Gemini, Alexa, and Cortana.

Principal Machine Learning Engineer 2026 – Present
Pinterest
Leading PINSAFE (a comprehensive safety taxonomy and framework for generative AI agents), PinValue (closing the feedback loop in content acquisition), and PinJev (a multimodal System One model for image+text classification at scale).
AI Researcher 2025 – 2026
Meta
Message recall and summarization for Meta's AI glasses.
Senior Staff Scientist / Manager 2022 – 2025
Google
Gemini safety (instruction following, safety heads, RL). Led PaLM Embeddings for Vertex AI. Built retrieval for NotebookLM and Semantic Retriever. Reduced Gemini overblocking by 50%.
Principal Applied Scientist 2020 – 2022
Amazon — Alexa
Led science for Natural Turn-Taking (Conversation mode). Mentored 60+ scientists and engineers. Authored three-year innovation roadmap. Advised Alexa Prize SGC4 teams.
Chief Scientist & SVP 2017 – 2020
Conversica
Led Conversational AI powering 1,500+ enterprise customers. Architected deep learning on 30M+ responses with pretrained transformers. Partnered with CEO and board.
Guest Faculty 2018 – 2021
UC Berkeley
Taught "NLP with Deep Learning" in the Masters of Data Science program.
Principal Applied Scientist 2016 – 2017
Microsoft — Cortana
Led conversational understanding across Cortana, Office 365, and LUIS. Delivered demos to Bill Gates and Harry Shum.
Assistant Professor 2013 – 2016
Northwestern University — Feinberg School of Medicine
Led 25+ affiliate members. 15+ grants from NIH, Novartis, AbbVie, Baxter. Clinical NLP for trial enrollment, EHR mining, and evidence synthesis.
Principal Investigator 2011 – 2013
Mayo Clinic
Operationalized cTAKES in Mayo's Enterprise Data Warehouse. Built NLP for AskMayoExpert clinical Q&A system.

Education

PhD, Biomedical Informatics
Arizona State University · 2008–2011
BTech, Computer Science and Engineering (Honours)
IIT Kharagpur · 2004–2008

Selected Honors

Keynote, AI with the Best
VentureBeat Top 5 AI Technologies
CB Insights AI 100 (Conversica)
NU Spark Award, Amazon
NIH Pathway to Independence Award
Gold Medal, Indian National Physics Olympiad
10th Rank, All India Engineering Entrance
Inlaks Award of Excellence at IITs

Writing

Technical books on machine learning and AI safety.

Forthcoming

Machine Learning: A Probabilistic First Approach

A comprehensive textbook that starts with probability — not loss functions — and never leaves it. Central thesis: maximum likelihood estimation and empirical risk minimization are two views of the same mathematical reality. Every chapter connects classical theory to modern AI (GPT, RLHF, diffusion models) and industry practice at the scale of hundreds of millions of users. No prerequisite beyond curiosity and basic algebra.

31 chapters 9 parts ~425 pages
Table of Contents
I. The Nature of Knowledge — Function approximation, probability from scratch, random variables, the IID assumption
II. Measuring the Distance to Truth — Distribution estimation, entropy, KL divergence, maximum likelihood
III. Two Sides of the Same Coin — Bayes classifier, ERM, bias-variance decomposition
IV. Taming Complexity — MAP estimation, regularization, nonparametric methods
V. The Linear World — OLS & GLS, logistic regression, cross-entropy
VI. Margins, Kernels, and Geometry — SVMs, max-margin, the kernel trick
VII. The Hidden and the Mixed — Mixture models, latent variables, EM algorithm
VIII. Neural Networks and Deep Learning — MLPs, backpropagation, CNNs, RNNs, transformers
IX. Beyond Supervision — PCA & K-means, VAEs, GANs & diffusion, LLMs, trees & ensembles, RL
Forthcoming

PINSAFE: Self-Evolving Safety for Agentic AI

with Wenke Zhang, Andrey Gusev, Francesca Anzola, Treesa Ann Jose, Christine Herlihy, Aravind Manickavasagam, Lisa O'Connor

A practitioner's guide to building safety systems for generative AI agents deployed at consumer scale. Traditional content moderation assumes harmful content arrives as discrete artifacts from identifiable actors — but AI agents that compose user data with generative capabilities produce emergent harms invisible to any single-component review. PINSAFE introduces a seven-dimension taxonomy (Privacy, Integrity, Nonmaleficence, Security, Accountability, Fairness, Explainability) comprising 52 harm types, grounded in GDPR, OWASP LLM Top 10, and NIST AI RMF. Covers red teaming, automated evaluation, intent gating, content filtering, and monitoring.

10 chapters ~300 pages 52 harm types
Table of Contents
1. Why Agentic AI Demands a New Defense Paradigm
2. The PINSAFE Framework — 7 dimensions, 52 harm types
3. System Model
4. Policies and Taxonomies
5. Red Teaming
6. Automated Evaluation and AART
7. Intent Gating and Routing
8. Content Filtering
9. Monitoring and Prevalence
10. Implementing the Target Agent

Selected Research

Highlights from 120+ publications and patents.

arXiv 2025
Gemini 2.5: Pushing the Frontier with Advanced Reasoning, Multimodality, Long Context, and Agentic Capabilities
Comanici G, ..., Jonnalagadda SR, et al.
arXiv 2024
Gemini 1.5: Unlocking Multimodal Understanding Across Millions of Tokens of Context
Reid M, ..., Jonnalagadda SR, et al.
arXiv 2024
Gecko: Versatile Text Embeddings Distilled from Large Language Models
Lee J, ..., Jonnalagadda SR, et al.
arXiv 2025
Backtracking for Safety
Sel B, ..., Jonnalagadda SR
arXiv 2025
BiasCause: Evaluate Socially Biased Causal Reasoning of LLMs
Xie T, ..., Jonnalagadda SR
NAACL 2022
Massive-scale Decoding for Text Generation using Lattices
Xu J, Jonnalagadda SR, Durrett G
Systematic Reviews 2015 · 365+ citations
Automating Data Extraction in Systematic Reviews: A Systematic Review
Jonnalagadda SR, Goyal P, Huffman MD
J Biomedical Informatics 2012 · 159+ citations
Enhancing Clinical Concept Extraction with Distributional Semantics
Jonnalagadda S, Cohen T, Wu S, Gonzalez G

Get in Touch

For speaking, collaboration, or questions about the book.