Daily Brief

Part of a series of monthly puzzles Early view of some other solutions: https://members.3blue1brown.com/posts/solution-to-10-158885046 https://members.3blue1brown.com/posts/solution-to-sum-156593740

An AI analyst at a firm like Bridgewater needs private documents, but every email, memo and research note carries its own permissions. Aaron Linsky (head of product engineering, Bridgewater Associates) explains why the Vault's 100 million permissioned documents broke their first search setup, and Nikhil Benesch (CTO, turbopuffer) breaks down the fix: post-filtering loses recall, pre-filtering is too slow, and "native filtering" over a clustered vector index gets both, delivering about 120ms P90 searches across 400 million vectors. Chapters 00:00 Intro: why permissions matter for AI analysts 0

Aparna Dhinakaran of Arize AI revisits what an AI engineer actually does as the field moves from writing features to running factories of agents. The job now is building the loop: evals that review non-deterministic work, telemetry that agents consume, and agents that act on it. She walks through how Arize built Signal, an always-on agent that reads traces, remembers past issues and opens PRs, covering triggers, sandboxes, durable state, and evaluating the evaluators. Chapters 00:00 Intro: what does an AI engineer do? 00:38 Karpathy's funnel: who's running thousands of agents 01:45 Rising abs

Full episode: https://www.youtube.com/watch?v=frYSOKvNiiE Me on twitter: https://x.com/dwarkesh_sp