Simon Willison’s Weblog
Includes performance optimizations written by Claude Opus 5.5 after I fed it this Python 3.15 profiling report generated by GPT-6 Astra.
Recent articles
Hello Python 3.15, goodbye 3.10, and now I can use 3.11 - 12th October 2026
A new feature for my blog, built using my voice - 9th October 2026
Claude Haiku 5.5 - 7th October 2026
We're going to need default hard budget caps on pretty much everything - 3rd October 2026
This is a beat by Simon Willison, posted on 13th October 2026 .
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