Simon Willison attended OpenAI DevDay 2026 in Fort Mason, San Francisco, and documented the event while adapting his personal workflow for the keynote. He initially attempted to build a photo-uploading system using Codex Cloud on his mobile device but encountered technical difficulties. Consequently, he switched to Claude Code for the web to manage the live blog updates. The session took place on 29th September 2026, with Willison securing a ticket and a seat in the creator area. Previous coverage from late September 2026 highlighted new pricing strategies and model releases including GPT-6 Sol and GPT-6 Luna alongside Claude Opus 5.5.
This shift in tooling illustrates how individual developers adjust their technical stacks when primary services fail during live events. The reliance on alternative coding assistants demonstrates the fragmented nature of developer productivity tools in 2026. Willison’s notes provide a raw account of the day’s proceedings without promotional language.
- Event location: Fort Mason, San Francisco
- Date: 29th September 2026
- Alternative tool used: Claude Code for web
