I've been having good results recently asking coding agents to provide "a linear walkthrough of the code that explains how it all works in detail" - I demonstrated that against this vibe coded Swift codebase and wrote up the technique here: https://simonwillison.net/guides/agentic-engineering-patterns/linear-walkthroughs/
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simon@fedi.simonwillison.net
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Wrote up a fun vibe-coding project, I had Claude Code build me a SwiftUI macOS app for presenting a talk by turning a list of URLs into a full-screen slide experience I could remote control from my phone https://simonwillison.net/2026/Feb/25/present/ -
Wrote up a fun vibe-coding project, I had Claude Code build me a SwiftUI macOS app for presenting a talk by turning a list of URLs into a full-screen slide experience I could remote control from my phone https://simonwillison.net/2026/Feb/25/present/Wrote up a fun vibe-coding project, I had Claude Code build me a SwiftUI macOS app for presenting a talk by turning a list of URLs into a full-screen slide experience I could remote control from my phone https://simonwillison.net/2026/Feb/25/present/
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New super-fast model from OpenAI today powered by their new Cerebras partnership - GPT-5.3-Codex-SparkNew super-fast model from OpenAI today powered by their new Cerebras partnership - GPT-5.3-Codex-Spark
It's 4-5x faster than GPT-5.3-Codex but the pelican isn't as good!
Here's its pelican compared to full GPT-5.3 Codex, both on "medium" https://simonwillison.net/2026/Feb/12/codex-spark/