Technology
Technology is the largest domain in scope: compute, storage, databases, networking, and management services, and matching a workload to the right service. The exam favors service-selection questions and basic architecture reasoning over deep configuration.
Compute
Amazon EC2 provides resizable virtual servers (IaaS), with instance types tuned for compute, memory, or storage. AWS Lambda runs code without provisioning servers and is event-driven, with a maximum execution duration of 15 minutes. Containers run on Amazon ECS or Amazon EKS, with AWS Fargate removing server management. AWS Elastic Beanstalk deploys applications while managing the underlying capacity.
Storage
Amazon S3 stores objects in buckets with storage classes for access frequency and retrieval needs; it is not a mounted file system. Amazon EBS provides block volumes attached to a single Availability Zone. Amazon EFS is a shared, elastic file system for Linux workloads across AZs. Amazon S3 Glacier classes are for archives. AWS Storage Gateway connects on-premises systems to AWS storage.
Databases and networking
Amazon RDS is a managed relational database service; Amazon Aurora is a MySQL- and PostgreSQL-compatible engine with higher performance and availability. Amazon DynamoDB is a managed NoSQL key-value and document database. Amazon Redshift is a data warehouse. Amazon VPC isolates networks with subnets, route tables, internet and NAT gateways. Route 53 is DNS, CloudFront is a CDN, and Direct Connect provides dedicated private connectivity.
Worked example
A static marketing site with a global audience and occasional traffic spikes. Host the files in an S3 bucket configured for static website hosting, put CloudFront in front for caching and TLS, and use Route 53 for DNS. Reasoning: no servers to patch, caching reduces latency, and S3 scales for spikes. If the site needs server-side logic, add API Gateway and Lambda rather than moving static assets to EC2.
Traps
Do not use S3 as a shared file system or EBS across AZs. RDS is not a NoSQL store. Lambda is unsuitable for long-running or stateful processes. CloudFront caches content and does not replace an application tier, and a NAT gateway allows outbound traffic but not inbound connections.