Deploying to the cloud for the first time requires deliberately designing for scalability, security, and cost, rather than simply lifting-and-shifting an application built for a single fixed server.
Key Points: • Make the application stateless where possible, moving sessions and file storage to managed services (Redis, S3) so any instance can handle any request. • Use cloud-native monitoring, logging, and autoscaling so capacity adjusts automatically to real traffic instead of being manually sized. • Apply security best practices from day one: least-privilege IAM roles, properly scoped firewall/security-group rules, and encryption in transit and at rest. • Manage credentials through the cloud provider's secret manager rather than baking them into images or config files. • Provision infrastructure with a tool like Terraform so environments are reproducible and reviewable, and set up billing alerts to avoid unexpected costs.
Example: A team migrating a monolith to AWS externalizes session state to ElastiCache, defines their VPC, subnets, and security groups in Terraform, and sets a CloudWatch billing alarm before going live, avoiding both a security gap and a surprise bill.
Interview Tip: A concise interview answer is:
"I'd design for statelessness and autoscaling from the start, using managed services for things like sessions and storage instead of a fixed server. Security and cost need equal attention upfront, so I'd apply least-privilege IAM roles, encrypt data, and provision everything through infrastructure as code so it's reviewable and repeatable."