What Does an AI Engineer Do Now? - Aparna Dhinakaran, Arize AI

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 abstraction, from code to agent factories 02:23 Then vs now: build the loop, not the feature 03:31 Signal: an always-on agent for your traces 04:45 Agents are now the main consumers of telemetry 05:19 What triggers an always-on agent 06:01 Inside a run: context, sandbox, proxy 07:11 What persists and what gets torn down 08:13 Designing durable agents 09:14 Model and harness agnostic 10:21 Writing evals, and evaluating the evaluators 12:48 Trace everything, including your coding agents 14:17 Closing the gap between labs and businesses Aparna Dhinakaran, Arize AI Join us in SF for the second annual AIE CODE summit: https://aie.codes our last flagship summit of 2026. Applications live now!