a16z Podcast

GPT-5 and Agents Breakdown – w/ OpenAI Researchers Isa Fulford & Christina Kim

Episode Summary

ChatGPT-5 just launched, marking a major milestone for OpenAI and the entire AI ecosystem. Fresh off the live stream, Erik Torenberg was joined in the studio by three people who played key roles in making this model a reality: - Christina Kim, Researcher at OpenAI, who leads the core models team on post-training - Isa Fulford, Researcher at OpenAI, who leads deep research and the ChatGPT agent team on post-training - Sarah Wang, General Partner at a16z, who’s led our investment in OpenAI since 2021 They discuss what’s actually new in ChatGPT-5—from major leaps in reasoning, coding, and creative writing to meaningful improvements in trustworthiness, behavior, and post-training techniques.

Episode Notes

ChatGPT-5 just launched, marking a major milestone for OpenAI and the entire AI ecosystem.

Fresh off the live stream, Erik Torenberg was joined in the studio by  three people who played key roles in making this model a reality:

• Christina Kim, Researcher at OpenAI, who leads the core models team on post-training
• Isa Fulford, Researcher at OpenAI, who leads deep research and the ChatGPT agent team on post-training
• Sarah Wang, General Partner at a16z, who helped lead our investment in OpenAI since 2021

They discuss what’s actually new in ChatGPT-5—from major leaps in reasoning, coding, and creative writing to meaningful improvements in trustworthiness, behavior, and post-training techniques.

We also discuss:

• How GPT-5 was trained, including RL environments and why data quality matters more than ever
• The shift toward agentic workflows—what “agents” really are, why async matters, and how it’s empowering a new golden age of the “ideas guy”
• What GPT-5 means for builders, startups, and the broader AI ecosystem going forward

Whether you're an AI researcher, founder, or curious user, this is the deep-dive conversation you won't want to miss.

Timecodes:

0:00 ChatGPT Origins

1:57 Model Capabilities & Coding Improvements

4:00 Model Behaviors & Sycophancy

6:15 Usage, Pricing & Startup Opportunities

8:03 Broader Impact & AGI Discourse

16:56 Creative Writing & Model Progress

32:37 Training, Data & Reflections

36:21 Company Growth & Culture

41:39 Closing Thoughts & Mission

Resources

Find Christina on X: https://x.com/christinahkim

Find Isa on X: https://x.com/isafulf

Find Sarah on X: https://x.com/sarahdingwang

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Please note that the content here is for informational purposes only; should NOT be taken as legal, business, tax, or investment advice or be used to evaluate any investment or security; and is not directed at any investors or potential investors in any a16z fund. a16z and its affiliates may maintain investments in the companies discussed. For more details please see a16z.com/disclosures