How does custom development integrate with CRM, ERP, payments, and analytics?

Custom development integrates with business systems through APIs, webhooks, and middleware layers. CRM integration (HubSpot, Salesforce, Zoho) typically uses REST APIs to push lead data from web forms into contact records, trigger workflow automation, and sync deal stage updates. ERP integration requires mapping website actions to inventory, order, or invoicing systems, often using middleware tools like Zapier for simple flows or custom-built integration layers for complex, high-volume data exchange.

Payment gateway integration with Razorpay, Stripe, or PayU involves server-side API calls for transaction initiation, webhook listeners for payment confirmation, and PCI DSS-compliant data handling to ensure card data never touches the web server. Analytics integration uses Google Tag Manager as the container for GA4 event tracking, Meta Pixel, LinkedIn Insight Tag, and custom conversion events, giving marketing teams a single management interface for all tracking without requiring developer changes for each new event.