What Backend Does Squarespace Use?
Squarespace is a proprietary, all-in-one platform rather than an open-source project, so it doesn’t publicly document its entire tech stack the way some open-source CMSs (like WordPress or Ghost) do. However, over the years, job listings, developer talks, and tech community findings have shed some light on the backend technologies Squarespace uses. Below is what’s generally known or inferred:
1. Proprietary Backend (Primarily Java/Scala)
Java & JVM Languages: Squarespace is known to use Java and occasionally Scala on the server side. It’s been confirmed through engineering job postings and some engineering blog posts that the core backend logic (template rendering, server-side commerce handling, etc.) is built around the JVM.
Monolithic & Microservices: Squarespace has grown significantly over time, so parts of the system may be split into smaller services (microservices) for e-commerce, image processing, analytics, etc. But from a user’s perspective, it’s still presented as one platform.
Because it’s proprietary, you can’t access or modify the backend source code—everything is closed off and hosted by Squarespace.
2. Hosting & Infrastructure
Squarespace-Hosted: You can’t self-host a Squarespace site. The service is fully hosted on Squarespace’s own infrastructure (historically a mix of leased servers and cloud solutions). They manage uptime, security patches, scaling, and performance behind the scenes.
Content Delivery & Asset Handling: High-traffic features, like image delivery, often rely on CDN configurations. If you check your site’s network requests, you’ll see your images are served from dedicated Squarespace or third-party CDN domains for faster global loading.
3. Database & Storage
Proprietary Data Layer: Squarespace manages your data (pages, blog posts, products, etc.) behind the scenes in their own database schema. They’ve never publicly stated if it’s MySQL, PostgreSQL, or a distributed database; we only know it’s not something you directly configure or access.
No Direct Database Access: As a user, you can’t connect to the backend database or run custom queries. You manage content via the Squarespace admin panel, which updates and stores everything in the platform’s servers.
4. Front-End Editing & Rendering
While the question is specifically about the backend, it’s worth noting how the front end interacts with it:
User-Facing Dashboard: Squarespace’s page and site editors run primarily in JavaScript/TypeScript, using frameworks like React for real-time drag-and-drop capabilities.
Template Rendering: Squarespace uses its own templating language (previously JSON-T for Squarespace 7.1), but you can’t modify the underlying rendering engine. In older Squarespace 7.0 templates, the template code was somewhat more accessible, but you still couldn’t access the raw server-side code.
5. No Traditional “Backend Access” for Users
Closed Ecosystem: Unlike WordPress or Shopify’s “Liquid” templating engine, you don’t install plugins on the server or edit server-side files. Squarespace extends functionality through code blocks, custom CSS, and limited code injection (header/footer) in the front end.
API Integrations: Squarespace does offer some official APIs for product management, orders, or custom checkout workflows, but these are client-facing or use token authentication. You never see the underlying server code or database.
6. Takeaways
Squarespace’s backend is proprietary and built largely with Java (and possibly some Scala), plus custom data storage and microservices.
The entire platform is Squarespace-hosted; you cannot self-host or access the underlying servers or database.
The user-facing front end, including the page editor, uses modern JavaScript frameworks (notably React) for the editing experience.
Customization typically happens at the front-end level (CSS, code blocks, limited code injection). The actual backend environment is locked down.
In short, Squarespace uses a proprietary Java/Scala-powered backend that is not exposed to end users. You interact only through their web interface and, to a limited extent, code-injection fields and APIs. While that may limit your control compared to an open-source CMS, it does simplify hosting, security, and maintenance for many site owners who want an all-in-one solution.