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Builders & Technical Leaders
Samuel Colvin
Creator & CEO |Pydantic
Created Pydantic (most used Python validation library) and Pydantic AI, bringing FastAPI-like ergonomics to agents.
GitHub
Open Source Projects
19 repositories · 83 total stars
cloudkv
key/value store for Python based on Cloudflare workers
Python333
uk-parliament-relatives
Python92
email-me
PWA to show a QR code with your email address.
HTML8
parplot
plot data from a parquet file
Python6
forgettable
TypeScript4
luck-or-judgement
Python4
qrcam
Rust3
tinicly
CLI for tinifying images and checking they're tinified.
Python31
Languages
Tech Stack
Python53%Rust16%HTML11%TypeScript11%JavaScript5%Go5%
Episodes
Podcast Appearances
10#
Title
Date
Dur.
1
Episode 71: Durable Agents - How to Build AI Systems That Survive a Crash with Samuel Colvin
2026-02-1851.4 min2
Pydantic: Open Source to VC backed company in 5 Years: A conversation with Samuel Colvin
2025-12-2236.6 min3
Pydantic AI with Samuel Colvin
2025-12-0457 min4
Building Production-Ready AI Agents with Pydantic AI
2025-10-0750.9 min5
Ep. 13 Samuel Colvin, Founder & CEO of Pydantic
2025-10-0237.4 min6
SE Radio 676: Samuel Colvin on the Pydantic Ecosystem
2025-07-1062.2 min7
Building Production Grade Agents with Samuel Colvin #58
2025-03-2049.5 min8
Agent Engineering with Pydantic + Graphs — with Samuel Colvin
2025-02-0664.1 min9
The story of Pydantic and Logfire | Samuel Colvin
2024-11-2835.5 min10
Samuel Colvin, Founder and Lead Maintainer of Pydantic
2023-03-2039.1 minBiography
Deep Research
Samuel Colvin is a Python and Rust developer and the Founder & CEO of Pydantic, a Sequoia-backed company building the data validation and AI agent infrastructure used by millions of developers. He started Pydantic in 2017 out of frustration that Python type hints did nothing at runtime, and curiosity about whether they could be used to validate data. What began as a side project is now downloaded over 300 million times per month and has surpassed 10 billion total downloads. Colvin holds an MEng in Mechanics and Fluid Dynamics from the University of Cambridge (2006-2010). Before Pydantic, he was Director and CEO of TutorCruncher. In 2023 he raised $4.7M seed from Sequoia, and in 2024 closed a $12.5M Series A to launch Pydantic Logfire (an observability platform) and Pydantic AI (an agent framework that became the fastest-growing agent framework by downloads in 2025). He is based in London, UK.
Data ValidationPython Type HintsAI Agent FrameworksRust PerformanceObservabilityOpen Source SustainabilityStructured OutputsModel Context Protocol (MCP)Durable ExecutionType Safety
Timeline
11 Research5 GitHub16 total
2026
2026Research
Pydantic surpassed 10 billion total downloads2025
2025-12-04Research
Appeared on Software Engineering Daily: Pydantic AI2025-10-07Research
Appeared on AI Engineering Podcast: Building Production-Ready AI Agents with Pydantic AI2025-09GitHub
Released Pydantic AI v1.0 — stable production release with MCP, graphs, and durable execution2025-07-10Research
Appeared on SE Radio #676: The Pydantic Ecosystem2025-04Research
Speaker at PyCon US 20252025-04-03Research
Appeared on AI Stories podcast S4E10: Pydantic, Logfire & PydanticAI2024
2024-12-19Research
MLOps Community Agent Hour #2: Why we built PydanticAI2024-10GitHub
Open sourced Pydantic AI agent framework2024-10-01Research
Raised $12.5M Series A led by Sequoia; launched Pydantic Logfire2023
2019
2019-10GitHub
Released Pydantic v1.0Key Contributions
Pydantic
The most widely used data validation library in Python, with 300M+ monthly downloads. Pioneered using type hints for runtime validation.
pydantic-core
Rust-based validation core powering Pydantic v2, delivering 5-50x performance improvements over the pure-Python v1.
Pydantic AI
Type-safe AI agent framework bringing FastAPI-like ergonomics to LLM agents. Fastest-growing agent framework by downloads in 2025 (8M/month).
Pydantic Logfire
AI observability platform for production LLM and agent systems, providing tracing, monitoring and debugging.
Jiter
Fast, iterable JSON parser written in Rust, used as the JSON parsing backend in Pydantic.
FastUI
Framework for building web UIs defined by Python code, using Pydantic models for the component schema.
Pydantic Open Source Fund
Annual fund investing $2,000+ per developer per year back into the open source ecosystem (currently $30k/year across 14 developers).
Notable Quotes
“
Back in 2017, when I first started it, the different thing it was doing was using type hints to define your schema. That was controversial at the time... today that's no longer controversial in Python.
“
Pydantic today is downloaded 300 million times a month. It's important to remember we're talking about GenAI today, but one of the powers of Pydantic is it is not just for GenAI.
“
For LLM agents to be reliable, they need a clear understanding of the tools they can access and the data they can expect — that's where Pydantic's principles of type safety become crucial.
12 sources(click to expand)
Samuel Colvin — personal websiteAbout Pydantic — Mission, Team & StorySamuel Colvin | Sequoia CapitalSequoia backs Pydantic (TechCrunch, Feb 2023)Sequoia backs Pydantic Series A (TechCrunch, Oct 2024)Agent Engineering with Pydantic + Graphs — Latent SpaceSE Radio 676: Samuel Colvin on the Pydantic EcosystemPydantic AI with Samuel Colvin — Software Engineering DailyBuilding Production-Ready AI Agents — AI Engineering PodcastPydantic Just Hit 10 Billion DownloadsExploring Pydantic with Samuel Colvin — SourcegraphDurable Agents with Samuel Colvin — Vanishing Gradients
Research generated March 19, 2026
Builders & Technical Leaders/Samuel Colvin
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