Facturalandia

Context

Facturalandia is an electronic invoicing platform for Mexico, compliant with CFDI 4.0. It is the only product in the ecosystem that is genuinely multi-tenant: each organization runs on its own Facturapi key encrypted with AES-256-GCM, its own self-registered signed webhook and its own storage buckets.

Architecture

A TypeScript monorepo (Turborepo) with five applications over a shared layer:

• apps/ — api (Express 5 + Mongoose), auth (login + 2FA), invoicing (the main app), materialization (read-only) and purchases.
• domains/ — business logic organized as vertical slices.
• shared/ — 10 packages: the API client, design system, SAT catalogs, Zod types and utilities.

Authentication is entirely in-house with argon2id — no third-party identity service. Real-time sync runs on signed Facturapi webhooks plus SSE to the clients; there is no Firebase anywhere.

Stack

• Runtime: Node 22. Backend: Express 5 + Mongoose (MongoDB).
• Frontend: React 19 + Vite 6 + TanStack Query + React Hook Form.
• Invoicing: Facturapi (CFDI 4.0). Payments: Stripe.
• Storage: Google Cloud Storage (PDFs and supporting documents).
• Deployed on Heroku; the monorepo is orchestrated with Turborepo.

Technical challenges

• The complete SAT cancellation cycle, with real-time notifications over signed webhooks + SSE.
• Mongo transactions on a replica set, and an idempotent backfill of historical invoices.
• Cross-cutting Spotlight search and background jobs whose logs stream over SSE.
• Real isolation between organizations: per-tenant encrypted keys, webhooks and buckets.

Outcome

A multi-tenant invoicing SaaS in production, where one shared layer — HTTP client, design system, SAT catalogs and Zod types — feeds authentication, invoicing, purchasing and materialization alike.