In a serverless architecture, Amazon API Gateway acts as the front door for applications to access backend services—especially AWS Lambda—over HTTP/S. It plays a critical role in managing and securing APIs without the need for server provisioning.
Amazon API Gateway is a fully managed service that allows you to create, publish, maintain, monitor, and secure REST, HTTP, and WebSocket APIs at any scale.

1. Monitoring Lambda Functions
A. Amazon CloudWatch Metrics
B. CloudWatch Logs
C. AWS X-Ray (Optional for Tracing)
2. Troubleshooting Lambda Functions

AWS WAF (Web Application Firewall) is a security service that helps protect your web applications from common web exploits and bots that can affect availability, compromise security, or consume excessive resources.

Amazon DynamoDB Streams is a feature that captures a time-ordered sequence of item-level changes (inserts, updates, deletes) in your DynamoDB table and stores this information for up to 24 hours.

Securing SSH access to your Amazon EC2 instances is critical for protecting your infrastructure from unauthorized access. Here are best practices and steps to secure SSH access:
*Use Key Pairs (Disable Password Login),
*Restrict Access with Security Groups,
*Use EC2 Instance Connect or Systems Manager (SSM),
*Use a Bastion Host / Jump Box,
* Rotate SSH Keys Regularly,
*Enable Logging and Monitoring,
*Harden SSH Configuration,
*Keep the OS and Packages Updated.