KYC Identity-Verification Onboarding Web App (Sumsub + Firebase)
A private offshore bank
Overview
A customer KYC (Know Your Customer) onboarding web app for a private bank, integrating the Sumsub identity-verification SDK with a Firebase serverless backend. End users complete document/identity checks in-browser while the backend handles authenticated token issuance and verification notifications. (Despite the folder name, this is an identity-verification product, not a web IDE.)
The Challenge
Regulated financial onboarding requires identity verification that is secure, compliant, and frictionless for the applicant. Sumsub’s API requires server-side HMAC-signed requests and short-lived access tokens that must never be exposed in the browser, so a trusted backend is mandatory.
What We Built
A React (Create React App) frontend that renders the Sumsub Web SDK (@sumsub/websdk-react) and drives the verification flow, persisting a per-applicant external ID across sessions. A Firebase Cloud Function (generateToken) called via react-firebase-hooks issues per-user access tokens, signing each Sumsub API request with an HMAC-SHA256 signature interceptor. The function layer also integrates SendGrid to email completed ID-scan results to the bank’s compliance inbox.
Technologies & Approach
React + Sumsub Web SDK for the in-browser verification experience; Firebase Functions for a serverless, callable token-issuance backend that keeps app tokens and secrets off the client; SendGrid for transactional compliance notifications. The HMAC request-signing interceptor follows Sumsub’s app-token security model.
Outcome / Impact
Delivered a working, deployed KYC onboarding flow that lets a bank verify applicant identity entirely in the browser while keeping credentials and signing server-side, a reusable pattern for regulated onboarding.
Capabilities Demonstrated
- KYC / AML identity-verification integration (Sumsub)
- Secure server-side token issuance and HMAC request signing
- Serverless backends on Firebase Cloud Functions
- Transactional email/notification integration (SendGrid)
- Compliance-grade onboarding flows for financial services