Migrating my portfolio from Next.js + Sanity to Astro 5

Originally published on ercan-atak.de.

I moved my portfolio from Next.js 14 + Sanity to a static Astro 5 site, and the short version is: the new site ships almost no JavaScript, has no external CMS, and drops every third-party network call that used to make GDPR compliance a chore. Content that once lived in a hosted Sanity dataset now lives in the repo as MDX and JSON, validated at build time. The only interactive JavaScript that reaches the browser is four small Svelte islands; everything else is server-rendered HTML with zero client runtime.

This post is the honest account of why I did it and what the trade-offs were — not a "Framework A beats Framework B" pitch. If you run a content-light personal site on a React meta-framework and a hosted CMS, most of this will apply to you.

Why leave Next.js + Sanity at all?

The old stack worked. The problem was that it was heavier than the job required. A portfolio with a handful of blog posts, some project write-ups, and image galleries doesn't need a React runtime on every page, and it doesn't need a hosted headless CMS with its own API, auth, and monthly moving parts.

Three things pushed the migration:

1. JavaScript I wasn't using. Next.js hydrates pages by default. Most of my pages are text and images — there was nothing to hydrate. I was paying a runtime tax for interactivity that only existed in two or three places.
2. A CMS I was renting for content I owned. Sanity is a good product, but my content is a dozen files. Putting them behind an external API meant a network dependency at build time and a second place to reason about schemas.
3. GDPR overhead. Operating a site under a real name from Germany means an Impressum and a Datenschutzerklärung, and every third-party call you make is something you have to disclose and justify. Fewer external calls is not just faster — it's less legal surface.

The architecture: server-first, islands rarely

Astro's model is the whole reason this works. Pages are .astro components that render to HTML at build time and ship zero JavaScript unless you explicitly opt in. Where I genuinely need the browser — a live clock, a mobile menu, the contact form, a custom cursor — I use a Svelte 5 island hydrated with the narrowest directive that fits:

• client:only for things that depend entirely on browser APIs (localStorage, document),
• client:visible to defer a below-the-fold form until it scrolls into view,
• client:idle for non-critical touches that can wait for the main thread.

The result is four islands total. Every other component is static HTML. There is no framework runtime on the critical path.

Content collections replaced the CMS

Instead of Sanity, content lives in Astro content collections: MDX for blog posts, JSON for the photography rolls, testimonials, and paintings. Each collection has a Zod schema, so a missing field or a wrong type fails the build instead of shipping broken. Adding a post is creating a file with the right frontmatter — it appears automatically, sorted and validated.

For the parts I want to edit without touching the repo, I wired a git-based CMS (Sveltia) that commits Markdown and JSON straight to GitHub. It's a thin editing layer over the same files — not a separate content backend. The source of truth is still the repository.

The GDPR wins were the real payoff

This is the part I underestimated. Going static let me remove entire categories of compliance risk:

• Self-hosted fonts. No Google Fonts CDN. A German court (LG München I, 3 O 17493/20) ruled that loading Google Fonts from Google's servers transmits a visitor's IP to the US without consent — and opportunistic claimants still send €100-per-pageview letters over it. I self-host the two font families locally; the browser never talks to Google.
• Cookieless analytics. I use a privacy-respecting, cookieless analytics setup with no persistent identifiers, which falls outside the German cookie-consent rules (§ 25 TDDDG). The site is genuinely cookie-free, so there is no cookie banner — and adding one would be pure UX cost with zero legal upside.
• Fewer processors to disclose. Every third-party call is a line in the privacy policy. Static hosting plus local content means the list is short and honest.

None of this is exotic. It's what you get "for free" when the default is to send nothing to the browser and nowhere off-origin.

What I gave up

Honesty section, because every migration has one:

• No on-demand rendering. Static output means content updates require a rebuild. For a portfolio that's a non-issue; for a news site it would be. Where I need freshness (image EXIF, a visitor counter), I fetch at build time or hydrate a tiny island.
• A migration is still work. Moving content out of Sanity, rebuilding every page as .astro, and rewiring the few interactive bits took real effort. The payoff is ongoing (every page load, forever), but the cost is upfront.
• React muscle memory. Astro and Svelte are not React. The concepts transfer, but the syntax and the hydration model don't. Budget a little ramp-up.

Would I recommend it?

For a content-light, interaction-light personal site — a portfolio, a résumé site, a small blog — yes, without hesitation. The static-by-default model matches the shape of the work, the zero-JS baseline is a real performance and privacy win, and owning your content as files in a repo is simpler than renting it from an API.

For an app with real interactivity on most pages, the calculus changes and a framework that hydrates by default may earn its keep. The point isn't that static wins — it's that the runtime should match the page. My pages are mostly text and photographs, so mostly they ship none.

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This whole site is the reference implementation. If you're curious how a specific piece works, the work section and the rest of the journal go into the details — and the colophon explains how the site itself is built.