● Open demo
Multi-tenant SaaS
Retail & FinTech
Passwordless auth
Data architecture
ChatBack
Product & data architecture, full stack · 2023–present
A multi-tenant loyalty and marketing platform for retail chains, operated
entirely through WhatsApp — no app to install. Every chain lives in the same database under
its own tenant: its own branches, its own programme, its own data, isolated from the rest.
Identity is passwordless: one-time codes delivered in the same WhatsApp
thread the customer is already in. Nothing to install, no password to reset, and the
verification lives in the channel itself — which is what makes it safe to attach a balance
to a phone number.
Sized against a real pipeline rather than a round number — the chains we pitched ran
3,600, 900 and 700 branches. The data model had to hold five thousand-plus
locations across tenants without the largest one degrading everyone else's queries.
At the core, a rigorous, normalized SQL ledger optimized for financial
auditability: virtual balances, real-time waitlists and micro-credit profiling
derived from transactional data. Double-entry rather than a mutable balance column, so every
movement is traceable and safe under concurrency — and deliberately architected as a
financial channel that never custodies funds.
Next.js · TypeScript · PostgreSQL · WhatsApp Business API · Webhooks
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