
Is plan mode dead? And other questions around the latest ChatGPT.
Coding Chats Episode 83 - In this episode, VB from OpenAI’s developer experience team explains why he thinks plan mode is obsolete and how coding agents have shifted from step-by-step instructions to outcome-driven, long-running work. We cover how to write a good agents.md, why tests still matter when agents write the code, spec-driven development, and why cloud agents may be the future of dev tooling. We also get into the practical details: how prompt caching works and why running one thread per task can cut your cost and latency, plus the biggest announcements from OpenAI’s Dev Day, including GPT 6.1 Sol, ultra fast inference, plugins, and proactive async agents. VB closes with the Codex Ambassadors program and Codex for open source. If you use Codex, AI coding agents, or any agentic coding workflow, there’s something here for you. 00:00 Introduction to Developer Experience at OpenAI 03:29 Bringing AI Models to Developers 06:06 The Shift from Planning to Outcome-Focused Development 09:05 The Role of Testing in AI Development 11:51 Creating Effective Agents.md for AI Projects 17:17 The Evolution of Developer Tools at OpenAI 25:21 Cloud Development: The Future of Coding 26:48 Insights from OpenAI's Dev Day 28:00 Revolutionizing Development with GPT 6.1 Soul 32:35 Understanding Caching for Developers 39:02 Proactive Agents: Enhancing Productivity 42:39 Community Initiatives and Open Source Contributions 48:36 Exploring Related Content VB's Links: https://openai.com/ John's Links: John's LinkedIn: https://www.linkedin.com/in/johncrickett/ John’s YouTube: https://www.youtube.com/@johncrickett John's Twitter: https://x.com/johncrickett John's Bluesky: https://bsky.app/profile/johncrickett.bsky.social Check out John's software engineering related newsletters: Coding Challenges: https://codingchallenges.substack.com/ which shares real-world project ideas that you can use to level up your coding skills. Developing Skills: https://read.developingskills.fyi/ covering everything from system design to soft skills, helping them progress their career from junior to staff+ or for those that want onto a management track. Takeaways Plan mode is obsolete because current models plan inherently, so you’re better off spending your time up front defining the outcome you want. Developers are moving from prescribing steps to defining intended outcomes (like “get this CI green”) and letting the agent plan, execute, and adjust on its own. Spec-driven development has its place, especially for API-shaped work, but it backfires if the spec isn’t kept in sync with every change. A strong but lightweight agents.md should cover where code lives, how the agent knows it’s doing a good job, your style rules, and what a good PR looks like. Tests still matter when agents write the code, because they catch regressions before merge, but the agent needs guidance on which tests are worth writing. Treat agents.md as a living document that grows as you work with the agent, not something you get right in one shot. To get the most from prompt caching, use one thread per feature and a couple of narrowly scoped subagents instead of running a dozen agents and letting the cache go cold. Coding workloads have large inputs and small outputs, which is why caching makes them so much cheaper and faster than typical chat use. Cloud agents are where dev tooling is heading, since they remove “works on my machine” problems and free long-running tasks from your laptop. If you’re still on the fence about coding agents, give one real task to an agent, watch how it interprets your request, and refine your instructions from there.



