Architecture

Rupert is a modular Rails monolith. Platform data flows in through a sync engine, lands in source mirrors, and is then lifted into a canonical domain core that the whole ERP reads from.

The sync pipeline

Shopify / Square
   │  (GraphQL / REST)
   ▼
SyncEngine.run! ─▶ CatalogSyncer ─▶ ShopifyProduct, ShopifyVariant, Location
   │               LedgerImporter ─▶ LedgerEntry
   │               SquareSyncer  ─▶ SquareItem, SquareVariation
   │               AlertGenerator ─▶ StockAlert
   ▼
CanonicalOrderImporter ─▶ Core::Order, Core::OrderLine, Core::Payment,
                          Core::Customer, Core::Fulfillment
   ▼
DataCache.bump!   (invalidate dashboard / report caches)

The importer is idempotent — it upserts on (tenant_id, source, source_order_id) and replaces line items, payments, and fulfillments each run, so the canonical store stays in lock-step with the feeds.

Modular monolith

Extensions live under app/modules/<name>/ and register themselves in app/models/module_registry.rb, which drives both navigation and the permission gate. The canonical domain core lives in app/modules/core/ and is the single source of truth for the ERP.

Background jobs

Syncs and their follow-up work run through Solid Queue. A sync enqueues post-sync work (notifications, sales announcements) that is fire-and-forget, so a slow worker can never block the sync run itself.

SyncSchedulerJob — kicks off a sync for every active tenant (every 15 minutes in production)
SyncJob — runs the engine, then enqueues notifications
BuzzNotifyJob — posts to the team's Buzz / Nostr channel
BackupJob — scheduled database snapshots to Google Drive

Permissions

Access is role-based with three resolution layers, checked through User#can? and Pundit policy objects:

Per-employee overrides (user_permissions) — exact grants for one person
Per-role overrides (role_permissions) — replaces the built-ins for a role
Built-in matrix (User::ROLE_PERMISSIONS) — the frozen defaults

Key directories

web/app/modules/core/      canonical domain (Order, Customer, Payment, Fulfillment)
web/app/modules/<module>/  per-feature controllers + views + policies
web/app/services/          sync engine, importers, presenters, platform clients
web/app/models/            module registry, users, settings, feature flags
web/app/views/             Tailwind UI (design tokens in app/assets/tailwind/application.css)