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Lenny's Podcast

Lenny's Podcast

Leadership, growth and business development 648,000 subscribers

Inside OpenAI: 2026 is the year of agents, AI’s biggest bottleneck, and why compute isn’t the issue

09.12.2025
Published: 09.12.2025 Category: Leadership, growth and business development

Episode details

Episode description

Alexander Embiricos leads product on Codex, OpenAI’s powerful coding agent, which has grown 20x since August and now serves trillions of tokens weekly. Before joining OpenAI, Alexander spent five years building a pair programming product for engineers. He now works at the frontier of AI-led software development, building what he describes as a software engineering teammate—an AI agent designed to participate across the entire development lifecycle. *We discuss:* 1. Why Codex has grown 20x since launch and what product decisions unlocked this growth 2. How OpenAI built the Sora Android app in just 18 days using Codex 3. Why the real bottleneck to AGI-level productivity isn’t model capability—it’s human typing speed 4. The vision of AI as a proactive teammate, not just a tool you prompt 5. The bottleneck shifting from building to reviewing AI-generated work 6. Why coding will be a core competency for every AI agent—because writing code is how agents use computers best *Brought to you by:* WorkOS—Modern identity platform for B2B SaaS, free up to 1 million MAUs: https://workos.com/lenny Fin—The #1 AI agent for customer service: https://fin.ai/lenny Jira Product Discovery—Confidence to build the right thing: https://atlassian.com/lenny *Transcript:* https://www.lennysnewsletter.com/p/why-humans-are-ais-biggest-bottleneck *My biggest takeaways (for paid newsletter subscribers):* https://www.lennysnewsletter.com/i/180365355/my-biggest-takeaways-from-this-conversation *Where to find Alexander Embiricos:* • X: https://x.com/embirico • LinkedIn: https://www.linkedin.com/in/embirico *Where to find Lenny:* • Newsletter: https://www.lennysnewsletter.com • X: https://twitter.com/lennysan • LinkedIn: https://www.linkedin.com/in/lennyrachitsky/ *In this episode, we cover:* (00:00) Introduction to Alexander Embiricos (05:13) The speed and ambition at OpenAI (11:34) Codex: OpenAI’s coding agent (15:43) Codex’s explosive growth (24:59) The future of AI and coding agents (33:11) The impact of AI on engineering (44:08) How Codex has impacted the way PMs operate (45:40) Throwaway code and ubiquitous coding (47:10) Shipping the Sora Android app (49:01) Building the Atlas browser (53:34) Codex’s impact on productivity (55:35) Measuring progress on Codex (58:09) Why they are building a web browser (01:01:58) Non-engineering use cases for Codex (01:02:53) Codex’s capabilities (01:04:49) Tips for getting started with Codex (01:05:37) Skills to lean into…

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