About
Noah Shinn founded Instinct, the invite-only AI assistant that venture investors bid from roughly $100 million to more than $2.5 billion in the space of a few weeks in August 2026 — before the product was even public. He is also the researcher behind two of the ideas the current agent boom runs on: Reflexion, the NeurIPS 2023 paper that taught language agents to critique their own failed attempts and try again, which he wrote as a Northeastern undergraduate, and τ-bench, the tool-agent-user benchmark he built as an early research scientist at Sierra, Bret Taylor's customer-service agent company. He left Sierra and registered Instinct's operating entity, Spear Street Technology, in California in April 2026.
Contact· published on Noah's own website
Beyond investing
- Founded
- Founded Instinct, registering its operating entity Spear Street Technology in California in April 2026 after leaving Sierra. The AI assistant was still invite-only in August 2026 when its valuation went from roughly $100 million to more than $2.5 billion in a matter of weeks.
- Communities
- Publishes open-source agent tooling on GitHub, including the reference implementation of Reflexion (3,000+ stars) and OpenTau, a Rust tool for repo-wide type prediction with large language models.
- More
- First author of "Reflexion: Language Agents with Verbal Reinforcement Learning" (NeurIPS 2023), written with fellow Northeastern undergraduate Federico Cassano and supported by MIT's Ashwin Gopinath and Princeton's Karthik Narasimhan and Shunyu Yao. Having the model verify its own work once lifted HumanEval accuracy to 91 percent, eleven points above the then state-of-the-art GPT-4 result. Built τ-bench, Sierra's benchmark for tool-agent-user interaction (ICLR 2025), which became a standard yardstick for agent evaluation in both academic research and industry. One of Sierra's first employees, working there as a research scientist before founding Instinct. At Northeastern worked in the Programming Languages Group on type prediction and code generation, and also with the Computational Photochemistry Group and the NU Aerospace avionics team. Co-authored "Can It Edit? Evaluating LLMs' Code Editing Abilities" (COLM 2024) and "Type Prediction With Program Decomposition". Instinct drew scrutiny in August 2026 when early testers circulated its terms of service, which claim a perpetual licence to user material and allow the assistant to enter binding agreements on a user's behalf. Shinn and the company did not respond publicly during the episode.
From Noah's own website — common ground for a warm intro.
Founder at Instinct
Intro paths
In turn, Noah can intro founders to Instinct's investors below.
Instinct's investors · 3
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Co-founders at Instinct
Experience
Writing
Built at Sierra with Shunyu Yao, Pedram Razavi and Karthik Narasimhan, and published at ICLR 2025. It scores an agent on conversations where it has to use tools and talk to a user at the same time, over several turns, and has become one of the standard yardsticks for agent evaluation.
A COLM 2024 benchmark, led by Federico Cassano, for a task the code benchmarks of the time skipped: changing code that already exists to match an instruction, rather than writing a function from a blank file.
The paper behind OpenTau: infer types across a whole repository by breaking the program into pieces small enough for a model to fill in, then type-checking the result.
Shinn's first-authored NeurIPS 2023 paper, written as a Northeastern undergraduate. Rather than update weights, the agent writes a plain-language critique of its own failed attempt and keeps it in memory for the next try — which took HumanEval to 91 percent, eleven points past the then-best GPT-4 result.
Frequently asked questions
- Who is Noah Shinn?
- Noah Shinn founded Instinct, the invite-only AI assistant that venture investors bid from roughly $100 million to more than $2.5 billion in the space of a few weeks in August 2026 — before the product was even public. He is also the researcher behind two of the ideas the current agent boom runs on: Reflexion, the NeurIPS 2023 paper that taught language agents to critique their own failed attempts and try again, which he wrote as a Northeastern undergraduate, and τ-bench, the tool-agent-user benchmark he built as an early research scientist at Sierra, Bret Taylor's customer-service agent company. He left Sierra and registered Instinct's operating entity, Spear Street Technology, in California in April 2026.
- Where does Noah Shinn work?
- Noah Shinn is Founder of Instinct.
- What companies did Noah Shinn found?
- Noah Shinn founded Instinct.
- Where did Noah Shinn go to school?
- Noah Shinn studied at Northeastern University (Khoury College of Computer Sciences).
- What has Noah Shinn written?
- Noah Shinn has 4 tracked posts on arxiv.org, including "τ-bench: A Benchmark for Tool-Agent-User Interaction in Real-World Domains", "Can It Edit? Evaluating the Ability of Large Language Models to Follow Code Editing Instructions", "Type Prediction With Program Decomposition and Fill-in-the-Type Training", and 1 more.