Cheat sheets

General Purpose (T3, M5), Compute Optimized (C5), Memory Optimized (R5, X1), Storage Optimized (I3, D2), Accelerated Computing (P3, G4).

• T3 instances are burstable – great for variable workloads
• Use Reserved Instances for steady-state workloads (up to 72% savings)
• Spot Instances save up to 90% but can be interrupted

Memory: 128 MB – 10 GB. Timeout: max 15 minutes. Deployment package: 50 MB zipped, 250 MB unzipped. Concurrent executions: 1,000 default.

• Use provisioned concurrency to avoid cold starts
• Lambda@Edge runs at CloudFront edge locations

Standard → Standard-IA → One Zone-IA → Glacier Instant → Glacier Flexible → Glacier Deep Archive. Use Lifecycle policies to transition automatically.

• S3 Standard: 99.999999999% durability (11 nines)
• S3 Standard-IA: min 128KB charge, 30-day min storage
• Glacier Deep Archive: cheapest, 12-48hr retrieval

EBS: block storage, single AZ, attached to one EC2. EFS: file storage, multi-AZ, NFS protocol, shared. S3: object storage, unlimited, REST API.

• EBS io2 for highest IOPS (64,000)
• EFS scales automatically, no provisioning
• S3 Transfer Acceleration uses CloudFront edges

VPC spans a Region. Subnets span an AZ. Internet Gateway for public access. NAT Gateway for private subnet internet. Security Groups are stateful, NACLs are stateless.

• Security Groups: allow rules only, evaluate all rules
• NACLs: allow + deny rules, evaluated in order
• VPC Peering: no transitive peering