So Payment gateway is a merchant service provided by an e-commerece. Moreover a payment gateway facilitates a payment transaction between a payment portal (such as a website, mobile phone or interactive voice response service) and the front end processor or acquiring bank.
Most importantly team worked with most popular Payment Gateway and API Integration,for e.g. Braintree, Gpwebpay, Instamojo, Quickpay, Inipay, PerfectMoney, Webpay, Blockchain,stripe.