Grupo Andreazzi — multi-company back office with a WhatsApp bot.

A business group is several companies that share people but not numbers. Running one system per company means reconciling spreadsheets at the end of every month; running one shared system means a finance lead of company A can read company B by accident. Neither is acceptable.

And the people who generate most of the data — the ones approving a payment, closing a checklist, confirming a meeting — are not going to open a laptop to do it.

One portal, one database, hard tenant isolation. Every company gets a slug-scoped workspace covering payables and receivables, categories, bank accounts, sales channels and goals, tasks, meetings, checklists, quarterly objectives, a calendar, file storage and a password vault.

• Per-company theming. Each company carries its own brand colours, injected as CSS variables at the layout boundary — the same screen reads as a different product in each workspace.
• WhatsApp bot. The parts of the job that happen away from a desk happen in a conversation instead: the bot understands intent through Claude, respects the same permission matrix as the web portal, and writes to the same tables.
• Notification engine. Rule-based alerts, subscriptions, and a templated daily digest, driven by five cron routes.

A Next.js monolith with a deliberately thin seam: everything tenant-scoped flows through a single company-context resolver and a role × module × action permission assertion. Seven roles, an explicit matrix, and a super-admin bypass that is itself auditable.

• Money is never a float. Decimal columns and decimal.js throughout, by project convention — an income statement that disagrees with itself by a cent is worse than no income statement.
• Bank reconciliation. OFX statement parsing with its own test suite, matched against booked entries.
• Vault. Shared credentials encrypted with AES-256-GCM under a master key held outside the database.
• Bot observability. Sessions, logs and raw messages are persisted, with an admin screen to watch conversations in flight — a conversational interface you cannot observe is a conversational interface you cannot fix.

The group runs its finance, commercial and planning routines in one place without any company being able to see another. The monthly close stopped being a spreadsheet merge, and the data that used to arrive late — or not at all — now arrives as a WhatsApp message the moment it happens.