SAA-C03 exam domain breakdown

Domain 1 — Design Secure Architectures (30%). Domain 2 — Design Resilient Architectures (26%). Domain 3 — Design High-Performing Architectures (24%). Domain 4 — Design Cost-Optimised Architectures (20%). Domains 1 and 2 together make up 56% of the exam — prioritise IAM, VPC, and multi-AZ/multi-region patterns first.

Services you must know cold

EC2 (instance types, storage, networking), S3 (storage classes, lifecycle, replication), RDS + Aurora (Multi-AZ, Read Replicas, backups), VPC (subnets, route tables, security groups, NACLs), IAM (policies, roles, STS), CloudFront + Route 53, Lambda + API Gateway, SQS + SNS, ELB (ALB vs NLB vs CLB).

The Well-Architected Framework — your exam cheat code

When two answers both look correct, apply the six pillars: Operational Excellence, Security, Reliability, Performance Efficiency, Cost Optimisation, Sustainability. The correct SAA-C03 answer almost always favours: managed services over self-managed, most cost-effective solution, least operational overhead, highest availability for the stated budget.

Common SAA-C03 question traps

RDS Multi-AZ is for high availability (failover), not performance. Read replicas are for read scaling, not failover. S3 is object storage — it's not a file system. SQS standard = at-least-once delivery. FIFO = exactly-once + ordering. EC2 Auto Scaling handles demand spikes; it's not a substitute for proper instance sizing.

6-week SAA-C03 study plan

Week 1: EC2, S3, IAM fundamentals. Week 2: VPC, networking, security groups. Week 3: RDS, DynamoDB, caching (ElastiCache). Week 4: High availability — ELB, Auto Scaling, Route 53, CloudFront. Week 5: Serverless (Lambda, API Gateway, SQS, SNS, EventBridge). Week 6: Full mock exams daily, review all wrong answers against AWS docs.