AWS SAA-C03 Tips

💥 Trap 1: IAM’s Silent Assassin — DENY rule

The Trap: You think an ALLOW policy grants access, but a hidden DENY in another policy nukes it.

The Fix:
IAM evaluates policies in this order:
1️⃣ Explicit DENY → 2️⃣ Explicit ALLOW → 3️⃣ Default DENY.

Imagine DENY is Thanos — it snaps ALLOW out of existence.

Always check for sneaky DENY rules!

💥 Trap 2: Security Groups vs. NACLs

The Trap: Mixing up stateful (Security Groups) and stateless (NACLs) rules.

The Fix:

NACLs are like airport security — check everyone in and out.

SGs are lounge staff — once you’re in, you’re good to go!

💥 Trap 3: S3 Versioning

The Trap: Enabling versioning, then realizing you can’t disable it — only suspend it.

The Fix:

• Use versioning only for critical data.
• Need to “disable”? Start fresh with a new bucket.

S3 versioning is like tattoos: easy to add, impossible to remove fully.

💥 Trap 4: Route 53

The Trap: Using a CNAME for example.com (instead of www.example.com).

The Fix:

• ALIAS records for apex domains.
• CNAME only for subdomains.
• CNAMEs can’t be used at the zone apex; you must use ALIAS or A records.

CNAMEs at the apex are like using a phone charger as a Wi-Fi antenna — it just doesn’t work that way.

💥 Trap 5: RDS Multi-AZ vs. Read Replicas

The Trap: Using Multi-AZ for read scaling (spoiler: it’s for failover only).

The Fix:

Multi-AZ is for survival — failover and resilience.

Read Replicas are for growth — read scaling and performance.

💥 Trap 6: CloudTrail vs. CloudWatch Logs

The Trap: Using CloudWatch for API audits (it’s for app logs).

The Fix:

CloudTrail: Who deleted my S3 bucket? (API tracking).

CloudWatch: Why is my app crashing? (debugging).

💥 Trap 7: Spot Instances

The Trap: Running mission-critical apps on Spot Instances (they can vanish mid-task).
The Fix:

Spot instances should be used for:

• Batch processing
• Stateless workloads
• Non-urgent tasks

Spot Instances are like tinder dates: cheap, fun, but don’t expect commitment.

💥 Trap 8: Time Management

The Trap: Spending 4–6 minutes on one question.

The Fix:

1. Answer easy questions first (2 mins each) and flag the rest.
2. If you’re not sure and need to take a guess, try to eliminate one or two wrong answers before making a choice.
3. Once you eliminate the wrong ones, look for word differences between the remaining options. One of them will make more sense than the rest 🙂