Claude Haiku

Voice Agents That Handle Interrupts - Chintan Agrawal and Daniel Wirjo, AWS

Jul 20, 2026 · 32:57

AWS Solutions Architects Chintan Agrawal and Daniel Wirjo argue that the hardest problem in production voice agents is audio engineering—not AI—specifically turn-taking, the decision of when an agent should stop speaking or start responding. They present three levels of turn detection: Level 1 uses Silero VAD with a silence timeout (e.g., 300ms default), Level 2 delegates to STT providers like Cartesia or Deepgram for built-in endpointing (p50 ~250-300ms), and Level 3 combines Silero VAD with SmartTurn, an open-source 8MB model achieving 58.9% recall and 68.4% precision while falling back to VAD on low confidence. They show how interruption handling (barge-in) flushes TTS/LLM in ~15ms and distinguish real interruptions from backchannel acknowledgments. Latency budgets are tight: 40ms mic encoding, 52ms network/jitter, 300ms STT+endpointing, 500-650ms LLM time-to-first-byte (dominant bottleneck), and 120-190ms TTS playback, totaling 800-1300ms in standard cloud setups. Co-locating models in one GPU cluster can achieve ~500ms voice-to-voice. For LLMs, Nemotron 3 Ultra and GPT-4.1 achieve ~530ms p50 but GPT-4.1 spikes to 1.7s p95, and multi-turn drift (>15 turns) can break prompt…

Your Agent Is Wasting Tokens and You Don't Know It - Erik Hanchett, AWS

Jun 28, 2026 · 5:55

Erik Hanchett, a Senior Developer Advocate at AWS, presents five specific techniques to reduce token costs in agent workflows without changing prompts or models. He demonstrates caching system prompts with 'cachePrompt' to avoid resending full context, and routing tasks by difficulty using cheaper models like Claude Haiku for simple requests. He advises offloading large tool results by storing them externally and sending only summaries, capping tool loops with a max iterations setting to prevent infinite loops, and trimming conversation history using a sliding window that keeps only the last 10 messages while optionally summarizing older context. These methods directly address common cost pitfalls, such as using expensive models for trivial tasks and letting context windows grow unchecked.

Ship Real Agents: Hands-On Evals for Agentic Applications — Laurie Voss, Arize

May 14, 2026 · 2:04:18

Laurie Voss, head of developer experience at Arize AI, delivers a hands-on workshop on evaluating agentic applications using Arize Phoenix, demonstrating that choosing the right eval matters more than tuning it: a correctness eval scored 0 out of 13 on the same financial analysis agent that a faithfulness eval scored 13 out of 13, because the model doesn't know the current year and cannot verify forward-looking data. He walks through building a complete eval pipeline from scratch—starting with tracing a Claude Haiku-based financial agent, reading and categorizing traces to identify root causes, then implementing code evals, built-in LLM-as-a-judge evals, and a custom actionability rubric with labeled examples. Voss emphasizes the importance of meta-evaluation to validate judge accuracy and introduces Phoenix experiments to prove prompt changes actually improve scores, not just vibes. Practical tips include using the impact hierarchy (data quality > prompting > model selection > hyperparameters) and the value of regression evals for safe model upgrades. The workshop closes with cost-aware evaluation, pairwise evaluation, and reliability scoring as next steps beyond the foundations…

[Full Workshop] Building Metrics that actually work — David Karam, Pi Labs (fmr Google Search)

Jul 29, 2025 · 40:28

Achim and David Karam, former Google Search leaders now at Pi Labs, argue that building reliable AI evaluations requires a multi-signal scoring system rather than single LLM-as-judge metrics. They walk through designing custom metrics starting with simple correlated signals, using a copilot to generate and iterate on dimensions like 'includes insights' or 'title length,' then calibrating them against ground truth thumbs up/down data from users. The workshop demonstrates applying this to a meeting summarizer, integrating the scoring system into Google Sheets to score 120 examples and produce a confusion matrix showing alignment with human feedback. They also show how to use the same scoring system for model comparison (e.g., GPT-1.5 vs 2.5) and online best-of-N sampling, which boosts response quality by generating multiple responses and selecting the highest-scored one.