AWS Developer Associate (DVA-C02) Cheat Sheet.
The night-before summary, built like the exam.

AWS Certified Developer - Associate (DVA-C02): Cheat Sheet

A fast-reference guide for last-mile review before sitting the AWS Certified Developer - Associate exam.

Exam Logistics At-a-Glance

• The unscored questions are indistinguishable from scored ones, so treat every question as if it counts.
• Online-proctored appointments are generally bookable 24/7, which gives more flexibility than a test-center slot.
• Scheduling happens through Pearson VUE, accessed via your AWS Certification Account.
• You can reschedule an appointment up to 24 hours before the scheduled time, and each appointment allows at most two reschedules — plan bookings with that ceiling in mind.

Content Domains (Official Weighting)

1. Development with AWS Services — 32% of scored content. The largest domain; expect heavy coverage of SDKs, APIs, Lambda, DynamoDB, and serverless patterns.
2. Security — 26% of scored content. IAM roles/policies, encryption (KMS), Cognito, and secrets management dominate here.
3. Deployment — 24% of scored content. CI/CD pipelines, CodeDeploy/CodePipeline, and deployment strategies (blue/green, canary).
4. Troubleshooting and Optimization — 18% of scored content. Root-cause analysis using CloudWatch, X-Ray, and logs; performance tuning.

The exam guide defines exactly 4 content domains — allocate study time roughly proportional to these weights, front-loading Development and Security since together they cover the majority of scored questions.

Key Terms and Concepts to Memorize

• Lambda concurrency — reserved vs. provisioned concurrency, cold starts, and execution context reuse.
• DynamoDB — partition keys vs. sort keys, GSIs vs. LSIs, eventually consistent vs. strongly consistent reads, DAX for caching, conditional writes for idempotency.
• API Gateway — REST vs. HTTP APIs, throttling, usage plans, caching, and Lambda proxy integration.
• IAM — difference between identity-based and resource-based policies; the policy evaluation logic (explicit deny always wins).
• STS and temporary credentials — AssumeRole, federation, and why you should never hardcode long-term keys in application code.
• CI/CD services — CodeCommit, CodeBuild, CodeDeploy, CodePipeline, and how they chain together.
• Deployment strategies — in-place, rolling, blue/green, canary, and linear — know when each is appropriate and how they map to CodeDeploy configurations.
• SQS vs. SNS vs. EventBridge — queue (pull, decoupling, dead-letter queues) vs. pub/sub (push, fan-out) vs. event bus (rules, schema registry).
• Step Functions — orchestrating multi-step serverless workflows, state machine types (Standard vs. Express).
• X-Ray — distributed tracing, segments, subsegments, and annotations for filtering traces.
• Elastic Beanstalk — deployment policies (all at once, rolling, rolling with additional batch, immutable) and configuration via `.ebextensions`.
• CloudFormation — intrinsic functions, stack sets, change sets, and drift detection.
• Secrets Manager vs. Parameter Store — automatic rotation vs. free-tier simplicity.
• KMS — envelope encryption, customer-managed vs. AWS-managed keys, and key policies vs. IAM policies.

Common Gotchas and Traps

• Questions often test the difference between similar-sounding services (SQS Standard vs. FIFO, DynamoDB Streams vs. Kinesis Streams) — read the full sentence before assuming.
• Watch for scenario questions where the "obvious" service choice is wrong because of a stated constraint (cost, latency, ordering guarantees).
• Lambda timeout and memory settings are frequently paired in tricky ways — increasing memory also increases CPU allocation, which can reduce duration and therefore cost.
• Idempotency traps: DynamoDB conditional writes and SQS deduplication IDs are common answers to "avoid duplicate processing" scenarios.
• Least-privilege IAM is almost always the "correct" security answer — be suspicious of any option granting broad wildcard permissions.
• Don't confuse deployment strategies: blue/green replaces the entire environment, canary shifts a percentage of traffic gradually, rolling updates a subset of instances at a time.
• CloudWatch Logs vs. CloudTrail: Logs capture application/service output, CloudTrail captures API calls and account activity — exam questions swap these deliberately.
• Exam questions may describe multi-domain scenarios (e.g., a security misconfiguration causing a deployment failure) — identify which domain the question is really testing before choosing an answer.

Night-Before Checklist

• Confirm your appointment time, delivery method (test center or OnVUE), and required ID match your AWS Certification Account details.
• If testing online, verify your room, webcam, and system meet OnVUE requirements — do this the night before, not the morning of.
• Review the domain weighting one more time: prioritize Development and Security flashcards since together they represent the majority of scored questions.
• Skim key term definitions rather than deep-diving new material — recognition matters more than fresh learning at this stage.
• Get sufficient sleep; a 130-minute exam with 65 questions rewards sustained focus over cramming.
• Know your reschedule policy in case of an emergency: appointments can be moved up to 24 hours ahead, and only twice per booking, so don't wait until the last minute to decide.
• Plan to arrive early (test center) or log in early (OnVUE) to handle check-in without rushing.