CPOS Pay and Hub Web App Development

Batuhan Ipci

Completed work

Mobile Engineer

Project Manager

Web Developer

AWS

Expo

Stripe

FinTech & Payments

CPOS Platform Case Study

About the Client - CPOS Inc.

CPOS Inc. is a Canadian technology company that provides payment processing, point-of-sale (POS) systems, and other tools to help small and mid-sized businesses streamline their operations.

Based in Ottawa, the company offers integrated solutions for sales, online ordering, and invoicing, specializing in payment processing to help businesses compete and grow.

The Challenge

CPOS needed a complete payment platform from scratch: a mobile app for accepting Tap-to-Pay transactions, a web dashboard for business management, and a robust backend to handle everything from subscriptions to KYC verification, while maintaining PCI compliance and supporting multi-party payment splits.

My Role: Full-Stack Engineer Timeline: 6 months Status: Production (Live)

What I Built

CPOS Pay Mobile App (React Native / Expo) – Tap to Pay on iPhone & Android via Stripe Terminal, transaction listing with advanced filtering, configurable tip and tax settings, invoice creation. Available on AppStore and Google Play

CPOS Hub Web Dashboard (React) – Role-based dashboard for merchants, admins, and support teams featuring real-time analytics, invoicing, transaction management, payout tracking, and business operations tools.

Merchant Onboarding & KYC Flow – Complete Stripe Connect integration with connected account provisioning, MCC code selection, automated identity verification (Stripe Identity), tiered subscription management, and intelligent transaction limit upgrades.

Technical Stack

Frontend: React 19, React Native, Expo SDK 53, TypeScript, Tailwind CSS Backend: AWS Amplify Gen 2, Lambda (Node 22), DynamoDB, AppSync, API Gateway Auth: Cognito (Email, Google OAuth, Apple Sign In) Payments: Stripe Connect, Terminal, Identity, Subscriptions Infrastructure: AWS CDK, CloudWatch, SES, Pinpoint SMS Monitoring: Sentry, Amplitude

Mobile: Tap-to-Pay Everywhere

Payment Flow (5 seconds from start to receipt): Enter amount → Add tip → Apply tax → Tap card → ✅ Instant receipt

Offline-First: Queues transactions when offline, syncs on reconnect

Smart Reader Management: Auto-connects/disconnects based on user settings

Device Detection: Automatically validates device compatibility

Watch me turn an iPhone into a payment terminal in 3 taps. No external hardware, no card readers, just pure NFC magic. ✨💳

Transaction History with Polish:

Smart Filtering: Search by amount, filter by status (Succeeded, Failed, Refund)

Grouped by Date: Automatic chronological grouping (Thursday, Monday, etc.)

Clean Indicators: Checkmarks for successful payments, clear failure states

Real-Time Updates: GraphQL subscriptions push new transactions instantly

📨 Digital Invoicing with Payment Collection

Complete invoicing system with email/SMS delivery and online payment:

Features:

Create invoices → Send via email/SMS → Payment page with Stripe Elements

Automated overdue detection and notifications

Full CRUD: Draft, send, resend, edit, cancel

Real-time delivery tracking (AWS SES + Pinpoint SMS)

Technical Implementation:

DynamoDB secondary indexes for fast filtering (businessId-status-dueDate)

Destination charges route payments directly to merchant accounts

Platform fee: 2.5% + $0.10 per transaction

Invoice system handling the full lifecycle: draft creation, automated delivery (email/SMS), overdue detection, public payment pages with 3D Secure, and instant status updates. Platform automatically calculates and collects 2.5% + $0.10 fee per transaction.

Web App: Real-Time Business Intelligence

Built a comprehensive analytics and operations dashboard:

Analytics

Revenue metrics with period comparisons (Today, Last 7/30 days)

Interactive charts (Recharts) showing sales trends

Next payout tracking with estimated arrival

Transaction breakdowns by payment method

Transaction Management

Advanced filtering (status, amount range, date, payment method)

Server-side pagination for large datasets

Detailed transaction drilldown with Stripe metadata

One-click refund processing with reason tracking

Role-Based Access

CPOS-Admin: Full platform access and operational tools

CPOS-Developers: Feature flags and testing utilities

Subscriber-TapToPay: Standard merchant features

POV: You're a small business owner who just collected $2.00 in tips and your dashboard treats it with the same importance as the $1,771 in sales. Equality. 🤝(Test environment data, but the real-time calculations and Stripe fee breakdowns work exactly like this in production)

Stripe Connect: Multi-Party Payments

Architected complete Stripe Connect implementation for platform + merchant splits:

Why Connected Accounts: Each merchant gets their own Stripe connected account, enabling:

Direct payouts to merchant bank accounts (daily automatic settlements)

Platform fee collection (2.5% + $0.10 per transaction)

Isolated balances per business for accounting clarity

Independent tax reporting (1099s issued to each merchant)

Onboarding Flow:

Business Profile Collection

Business type (individual vs. company)

MCC code selection (1000+ categories with search)

Business details, address (Google Places validation), tax IDs

Connected Account Creation

Automatic Stripe account provisioning

Capability requests (card_payments, transfers)

Metadata linking (businessId, subscriptionId)

Identity Verification (KYC)

Stripe Identity SDK integration

Biometric verification support

Automatic limit upgrades upon verification

Bank Account Connection

ACH (US) and ACSS Debit (Canada)

Multiple account management

Verification status tracking

Transaction Processing at Scale

Stripe Connect destination charges routing to merchant accounts

Subscription billing ($20 CAD recurring) + invoice payments ($110+ USD one-time)

Complete payment lifecycle handling: succeeded → refunded → disputed

Settlement tracking via "CPOS Pay Sandbox" connected accounts

Payment method variety: Visa cards ending in 4242, 3155, etc.

Behind Every Transaction: Each entry represents a Stripe webhook → DynamoDB Stream → Lambda processor → receipt generation → real-time dashboard update. The system processes webhooks, generates receipts, sends emails/SMS, and syncs data across mobile and web in real-time.

Transaction Processing at Scale

Test Environment Demonstrating Production Capabilities:

3,232 test transactions processed through Stripe Connect

2,208 succeeded payments with automatic settlement

214 refunds handled via webhook automation

6 disputes tracked through Stripe's dispute system

Multi-currency: CAD and USD support working side-by-side

What This Demonstrates:

Stripe Connect destination charges routing to merchant accounts

Subscription billing ($20 CAD recurring) + invoice payments ($110+ USD one-time)

Complete payment lifecycle handling: succeeded → refunded → disputed

Settlement tracking via "CPOS Pay Sandbox" connected accounts

Payment method variety: Visa cards ending in 4242, 3155, etc.

Smart Subscription System

Built tiered subscription model with dynamic transaction limits:

Subscription Tiers:

14-day free trial (no card required)

Basic: $250/transaction limit

Premium: $1,000/transaction limit

Intelligent Limit Upgrades: Automatically upgrades limits when users complete both:

Identity verification (Stripe Identity)

Active paid subscription

// Real-time upgrade via webhook processing
if (isVerified && isPaid && currentLimit < 100000) {
  await updateTransactionLimit(businessId, 100000);
  await sendUpgradeNotification(business);
}

Features:

Webhook-driven subscription management

Automatic Cognito group updates

Payment method management

Trial ending notifications

Reactivation flows for canceled subscriptions

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Completed work

Posted Oct 16, 2025

Developed CPOS Pay Mobile and Hub Web App with Stripe integration for Tap to Pay functionalities and merchant management.

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Timeline

May 1, 2025 - Ongoing