Building a secure payment gateway for your eCommerce mobile application development company is crucial to protect customer data and ensure trust. Start by selecting a trusted payment service provider with robust security features. Use encryption protocols like SSL/TLS to secure data transmission, and implement tokenization to replace sensitive data with tokens. Regularly update software and patch vulnerabilities. Employ multi-factor authentication for user accounts. Implement strong access controls and ensure PCI DSS compliance. Monitor transactions for anomalies and use fraud detection systems. Regularly audit and test your payment gateway for vulnerabilities. A secure payment gateway not only safeguards customer information but also fosters confidence, driving success for your eCommerce app.