Your application becomes slow during peak hours. Which AWS services can automatically handle increased traffic?

I am preparing for AWS interviews and came across this real-world scenario. Suppose a web application performs well under normal conditions but becomes slow during peak traffic hours due to a sudden increase in users.

I would like to understand:

Which AWS services can automatically scale the application based on demand?
How do Elastic Load Balancer (ELB) and Auto Scaling Groups work together to distribute traffic and maintain high availability?
When should services like Amazon CloudFront, AWS Lambda, or Amazon ECS/EKS be used to improve performance?
How can Amazon RDS handle increased database traffic using features like Read Replicas or Multi-AZ deployments?
Which monitoring and alerting services (such as Amazon CloudWatch) help detect and respond to performance issues?
Could you share a recommended AWS architecture for handling traffic spikes and ensuring the application remains available?