Connecting the website with the backend ( servers and database ) and making sure that all the desirable technologies are implemented in your application, which includes - 1. Custom API Development and Integration 2. User Authentication using Third Party Platforms ( Google, Facebook, Twitter, Github, etc. ) 3. Payment Gateway Integration ( Stripe, PayPal, Razorpay, CC Avenue, etc.) 4. Connecting Application with Third-Part Backend Services ( Firebase, Supabase, Appwrite, etc. )