
Vaultline – Business Finance Platform
Challenge
Businesses needed a service they could offer their clients to open financial accounts, top up and withdraw funds, move money between users, and issue virtual cards.
Solution
Built a full-stack platform with React, Firebase (Auth, Firestore, Cloud Functions), and Stripe Connect, Treasury, and Issuing. Delivered Connect onboarding, Treasury accounts, virtual cards with secure PAN reveal via Issuing Elements, webhook-driven account sync, and real-time authorization with spending limits. Added a middleware pipeline (auth, email verification, Stripe account resolution, card ownership) and Firestore rules that block client writes, plus fail-closed card authorization that checks status, Treasury balance, and merchant country before approving spend.
Result
Unified business banking in one dashboard with server-authoritative transfers, virtual card lifecycle, and real-time spend controls




