DVA-C02 — AWS Certified Developer Associate — AWS Study Hub

Exam Overview

Exam Details

Duration: 130 minutes
Questions: 65
Passing Score: 720/1000
Format: Multiple choice & multiple response
Cost: ~$150-300 USD
Validity: 3 years

🎓 Official Resources

Exam Domains

Domain	Weight
Development with AWS Services	32%
Security	26%
Deployment	24%
Troubleshooting & Optimization	18%

Lambda Deep Dive

Limits

Memory: 128 MB – 10,240 MB
Timeout: max 15 minutes
Temp storage (/tmp): 512 MB – 10 GB
Concurrent executions: 1,000 (soft limit)
Package: 50 MB zipped, 250 MB unzipped

Invocation Types

Synchronous — wait for result (API Gateway, ALB)
Asynchronous — no wait (S3, SNS, EventBridge); retries 2x; DLQ
Poll-based — Lambda polls (SQS, Kinesis, DynamoDB Streams)

Lambda Features

Versions — immutable snapshots of code + config
Aliases — named pointers to versions (PROD, DEV)
Canary / Linear deployments — gradual traffic shifts with CodeDeploy
Layers — reusable dependencies shared across functions
Container Images — up to 10 GB; use Lambda base images

DynamoDB for Developers

Concept	Description
Primary Key	Partition Key only (simple) OR Partition Key + Sort Key (composite)
GSI	Global Secondary Index — different partition key; eventual consistency
LSI	Local Secondary Index — same partition key, different sort key; must be at creation
Read Consistency	Eventually Consistent (default, cheaper) vs Strongly Consistent
DynamoDB Streams	Ordered record of item changes; trigger Lambda
TTL	Auto-delete items after expiry timestamp (free)
DAX	In-memory cache; microsecond read latency; write-through
Transactions	ACID transactions across multiple items/tables

CI/CD on AWS

Service	Purpose	Like
CodeCommit	Private Git repositories	GitHub/GitLab
CodeBuild	Build & test (compile, run tests, create artifacts)	Jenkins, GitHub Actions
CodeDeploy	Deploy to EC2, Lambda, ECS, on-premises	Spinnaker
CodePipeline	Orchestrate full CI/CD pipeline	GitLab CI
CodeArtifact	Artifact repository (npm, Maven, PyPI)	Nexus

CodeDeploy Deployment Strategies

Strategy	Behavior
In-Place (EC2)	Deploy to existing instances; brief downtime per instance
Blue/Green (EC2)	New instances; shift traffic via LB; zero downtime
All-at-once (Lambda)	Immediate 100% shift
Canary (Lambda/ECS)	X% traffic for N minutes, then 100%
Linear (Lambda/ECS)	Gradual shift X% every N minutes

API Gateway

REST API — full features, 29s timeout, edge-optimized or regional
HTTP API — simpler, 70% cheaper than REST API
WebSocket API — bidirectional; real-time apps, chat, gaming
CORS — must be enabled for browser cross-origin calls
Stages — dev, staging, prod; each can have throttling/canary settings
Usage Plans & API Keys — throttle and monetize APIs
Caching — reduce backend calls; TTL 0-3600s

Monitoring & X-Ray

CloudWatch

Metrics — every service sends metrics (CPU, requests, errors)
Alarms — trigger SNS/ASG when threshold breached
Logs — Lambda writes here automatically
Log Insights — SQL-like query language for logs

X-Ray

Distributed tracing for microservices & Lambda
Service Map — visual of all components
Requires: X-Ray SDK + X-Ray Daemon (EC2) or active tracing (Lambda)
Annotations (indexed) vs Metadata (not indexed)
Sampling rules — control % of requests to trace