Building an AI website builder, 6 weeks in: what I learned about multi-tenant SEO

AI Marcus — Fri, 01 May 2026 17:00:50 +0000

Six weeks ago I posted a Show DEV about AI Marcus, an AI website builder I'm building. The post got zero comments. That's fair — I led with marketing, not engineering. Here's the technical post I should have written.

The problem nobody warned me about: multi-tenant SEO

When you let users publish hosted sites under your domain, Google's default behavior will destroy your SEO if you don't architect for it.

Every hosted site at yoursite.aimarcus.eu or on a custom domain example.com needs to look to Googlebot like its own canonical entity, not like a path under aimarcus.eu. Get this wrong, and Google folds everything into duplicate-content limbo. Worse — your editorial pages get deindexed because Google thinks they're orphan tenant pages.

What I had to ship to fix this:

Per-tenant sitemap.xml generated dynamically from project metadata, pinned to the tenant's canonical host. Not the platform's sitemap.
Per-tenant robots.txt that points to the tenant's sitemap.
Absolute canonical and og:url on every tenant page, on the tenant's own host. Never /s/{slug}/.... If the AI generator emits a relative canonical, the routing layer rewrites it.
The platform's aimarcus.eu/robots.txt disallows /s/ and /blog/ for AhrefsBot specifically — otherwise Site Audit reports drown in "orphan page" alerts that aren't actually orphans, just multi-tenant.
IndexNow per-tenant keys. Each project gets a 32-hex key on first save, reachable at tenant-host/{key}.txt for ownership proof. Bing, Yandex, Naver, Seznam all read this.
Sitemap index at /sitemap.xml references the platform sitemap + a hand-maintained niche sitemap (108 URLs across 12 languages). Was getting wiped on every server restart by the auto-regenerator — fixed by making the niche sitemap part of the regenerator's output, not a side file.

The numbers (4 weeks of actual SEO traffic)

0 ranked keywords across EE / RU / UA / UK locales (DataForSEO check)
1 keyword ranking position 71-80 in US (negligible)
~20 organic clicks per month from Google
~3 clicks/month from ChatGPT (yes, Bing-routed referrers exist now)
1 paying customer

So this post is not a victory lap — it's a diary entry from the part of the journey where the architecture is finally right but the audience isn't yet.

What I'd skip if I started again

The blog with 343K programmatic city × niche pages. Google indexed none of them. Burned 1 GB of disk and 6 weeks of crawl budget for zero impressions. Killed it last week.
Service-account-only Google Search Console verification. The siteFullUser permission is enough for sitemap submit, but https://... URL-prefix property fails 403; only sc-domain: works. Save yourself the debugging.

Shipped today: built-in affiliate tracking

This morning a paying customer asked me one question: "does it support affiliate program tracking?" By evening I'd shipped a network-agnostic helper that captures a click_id from inbound URL into localStorage, fills any href / form action containing {click_id} with the live value, attaches a hidden click_id input to every form submit, and exposes window.aimMarcusConversion(amount, currency) which fires a postback pixel to the user's tracker on goal completion.

The placeholder map covers the 6 networks I see most often in this segment: Voluum, Affise, Tune (HasOffers), ClickMagick, Keitaro, Binom — plus generic. Users paste their postback URL with the network's native tokens ({sub1}/{payout}/{payout_currency} for Keitaro, {cid} for Voluum, {clickid}/{sum} for Affise, etc.) and the helper translates them at runtime.

The interesting design decision was rejecting the obvious "let users write JavaScript in a custom-code box" path. That's how spam pixels and tracker leaks get into otherwise clean tenant pages. Instead the helper is generated from a structured config (affiliate.network, affiliate.postbackUrl, affiliate.clickIdParam) and validated server-side: no postback URL = no script, postback URL must be HTTPS, click-id param sanitized to [A-Za-z0-9_-]{1,40}. The blast radius is bounded.

What's next

Toolify auto-discovered the listing on Apr 13. Bing's giving us 12% conv on 17 visits. The funnel finally shipped clean. Now I need to move "page visit → input click" from 11% to 25% and figure out an honest acquisition motion for the Stripe markets.

Site: https://aimarcus.eu — first generation is free, no signup.
Repo: not open-sourced. Happy to share architecture details in comments.

Show DEV: AI website builder that generates a complete site in 60 seconds

AI Marcus — Sat, 18 Apr 2026 22:42:53 +0000

Built an AI website builder where you describe your business in natural language and get a complete website in about 60 seconds.

Live demo (no signup required): aimarcus.eu

What it generates

Unique design (not templates — each site is generated from scratch)
Copywriting tailored to the business niche
AI-generated hero and section images
SEO basics: meta tags, JSON-LD schema, canonical, hreflang
Mobile responsive, semantic HTML
Free hosting included, or download full source code

Stack

Generation: Claude (content + code), Imagen 4 / DALL-E 3 (images)
Backend: Node.js + Express, PostgreSQL
Multi-agent workflow: designer → copywriter → SEO pass
Languages: 35 localizations out of the box
Niche pages: /for/restaurants, /for/dentists, /for/barbershops, etc.

The "zero-to-wow" approach

Instead of asking for signup first, the landing page has a prompt input. Type your business in one sentence → see the generated site before deciding to pay. Converts dramatically better than the traditional "sign up, enter credit card, then try" funnel.

Pricing

Free first generation (to see the output quality)
€20/page when you publish
14-day money-back guarantee
Full source code delivered (HTML/CSS/JS)

Questions for DEV

What do you think about the quality of the generated code? (Check the "View source" on any generated site.)
We're debating whether to open-source the "layout planner" agent — would that be useful?
Any niches we're missing? Current set: restaurants, barbershops, dentists, lawyers, gyms, yoga, photographers, real estate, auto repair, construction.

Freelancers: there's a 30% lifetime commission partner program at aimarcus.eu/partners.

Happy to answer anything in the comments.

DEV Community: AI Marcus