Sanity's Internal Tech Stack: GROQ Language, Datastore, and Infrastructure

Great question! While Sanity doesn't publish exhaustive details about every internal implementation choice, there's actually some solid information available about their tech stack from a community discussion thread and a blog post about open sourcing GROQ.

Tech Stack Overview

Query Engine & Language:

• The GROQ query engine is written primarily in Go, which makes sense for performance-critical query processing
• Many of Sanity's services are built with JavaScript/TypeScript
• GROQ (Graph-Relational Object Queries) development started in 2015, led by Simen Svale Skogsrud and Alexander Staubo, with Erik Grinaker contributing work on consistency
• Magnus Holm built Glush, a "parser-parser" that generates GROQ parsers for different languages (including JavaScript)

Data Storage:

• Uses both PostgreSQL and Elasticsearch for storage
• This dual-database approach likely leverages Postgres for transactional data and Elasticsearch for search/query capabilities

Infrastructure:

• Runs on Google Cloud Platform
• Uses Kubernetes (K8s) for orchestration
• Leverages Google's CDN for content delivery

The GROQ specification was open-sourced in 2019, and there's also a CLI tool you can use to experiment with GROQ queries against JSON data.

GROQ Design Influences

GROQ was designed specifically for querying JSON documents with a focus on:

• Human readability and expressiveness
• Filtering, projection, and joining capabilities
• Graph-relational traversal (hence the name)
• Working naturally with nested/hierarchical content structures

The precursor to Sanity was a project called Pebbles, which influenced some of the design decisions.

Sanity vs Prisma/Hasura

Regarding comparisons to Prisma Server and Hasura - I couldn't find official comparison content from Sanity on this. However, the key architectural difference is:

• Hasura/Prisma are primarily GraphQL layers over existing databases, auto-generating APIs from your database schema
• Sanity is a complete content platform with its own storage layer, query language (GROQ), real-time capabilities, and content-specific features like the Studio editor

Sanity is purpose-built for content operations, whereas Hasura/Prisma are more general-purpose database API layers. They solve different problems - Sanity competes more directly with headless CMS platforms like Contentful or Strapi, while Hasura/Prisma are tools for building APIs on top of your own database.

The choice between them really depends on whether you need a managed content platform (Sanity) or want to build your own data layer with GraphQL tooling (Hasura/Prisma).