The Astro 5 to 6 migration looked like a ten-minute security bump. Instead I hit three build failures back to back — every one of them in vendored theme code I never wrote. Here are the exact errors, the fixes, and why a themed site breaks where your own code doesn't.
A title tag and a meta description aren't an SEO setup — they're the part every template already gives you. The plumbing that compounds (JSON-LD, canonicals that don't 404, hreflang that doesn't backfire, a clean sitemap) is what portfolios skip. Here's my full Astro SEO setup, real code included.
Every new session with an AI coding assistant starts blind — it can't remember why you rejected that approach three weeks ago. The fix isn't a bigger context window, it's persistent memory across sessions, layered. Here's the pattern: native memory for the live thread, a file index for durable facts, and a semantic second brain for everything older.
Publishing a static Astro post is one merge away from live — which is exactly why the silent bugs are dangerous. A wrong lang, a canonical that 404s, a leaked cross-language link: none of them show up in your editor, only in the built HTML. Here's the checklist I run on dist/ before every post, scripts included.
My Google Analytics was installed, verified, and collecting absolutely nothing — with zero errors to warn me. The culprit was a Partytown default in my Astro theme that emits GA as a script the browser never runs. Here's the trap, and the one-line fix.