AI won’t fix healthcare unless it starts with the conversation.

In this episode, Zachary Lipton—Chief Technology & Science Officer at Abridge and Raj Reddy Associate Professor of Machine Learning at Carnegie Mellon University—joins Barr Yaron for a deep, technical, and emotional dive into how AI can truly transform clinical care.

From building a world-class ambient documentation system to tackling speech recognition in 28 languages, Zack shares what it takes to engineer trust into AI when the stakes are patient lives, not just clicks.

We cover:

Why general-purpose models fail in clinical settings

How Abridge designs for accuracy, context, and trust

The tension between personalization and evaluation

Why ambient AI might be the most promising foundation for fixing healthcare

This is one of the most in-depth looks at what it actually takes to build production-grade AI in medicine.

This episode is broken down into the following chapters:

00:00 – Intro

00:34 – What Abridge actually does (hint: it’s not just notes)

01:09 – Why documentation is killing the healthcare experience

03:05 – How we got to the current burnout crisis

04:16 – The key insight: healthcare is a conversation

07:33 – Building a digital scribe: the original vision for Abridge

09:15 – Why off-the-shelf models don’t cut it in clinical speech

11:36 – 28 languages, noisy ERs, and overlapping conversations

13:20 – Predicting what enters the medical lexicon next

14:21 – How Abridge adapts models for edge-case medical speech

15:18 – Beyond transcripts: the complexity of clinical note generation

17:10 – Foundation models are tools, not solutions

18:06 – The “Ship of Theseus” strategy of model orchestration

20:32 – Style transfer for doctors, patients, and payers

20:54 – Metrics: ASR evaluation vs. documentation quality

23:43 – Stratifying ASR performance by setting, language, and jargon

24:50 – Why eval is so hard when there’s no “gold note”

25:45 – The tension between personalization and general eval

28:05 – Lessons from machine translation: building robust eval pipelines

30:32 – Abridge’s “look at the f*cking data” (LFD) internal review

33:54 – Blinded clinical eval with linked evidence and audio

36:50 – Why human fallibility is just as real as AI hallucination

38:21 – What kind of CTO Zack actually is

40:32 – Why AI product development is its own discipline

42:44 – AI innovation now lies in the product-data-model loop

44:25 – Closing the loop: how design drives modeling

45:25 – How Abridge hires researchers who care about product

47:29 – The mission filter: if you’d be equally happy at Microsoft, go

49:35 – What’s next: the AI layer for healthcare, not point solutions

52:57 – Closing thoughts

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