Day 31

Today, I:

• discovered the ombulabs/claude-code_rails-upgrade-skill via Ruby Weekly — should be genuinely useful for the Rails 7.2 → 8.1 upgrade we're planning at Spacely
• watched Apache Spark — The Ultimate Guide up to 3:50:46 — Ansh Lamba's delivery is funny and conversational, like a buddy walking you through it, which makes a 6-hour course actually finishable; learned a lot about Spark already and will finish the rest tomorrow
• shipped a chat feature at /en/chat — a Next.js streaming API route that pipes Claude Sonnet 4.6 deltas straight to the browser via a ReadableStream, with the system prompt rebuilt per request from a curated persona Markdown file plus a digest of every post in the active locale (title, date, category, tags, excerpt), all wrapped in cache_control: ephemeral so follow-up turns hit the prompt cache; user messages get Zod-validated and react-markdown renders the streamed bubbles; not really a digital clone — more an LLM augmented with this site's content — and the same UI ships in fr and ja too