WGU D321 AWS DEVELOPER DVA-C02
CERTIFICATION SCRIPT 2026 QUESTIONS
WITH SOLUTIONS GRADED A+
◍ What are the type of Primary Keys for DynamoDB.
Answer: Partition KeyPartition key based on a unique attribute. Composite
key is a combination of (partition key + sort key). It is used when partition
key is not unique. sort key can be a timestamp
◍ What Athena.
Answer: Its an Interactive query service.Enables user to run standard SQL
queries on data stored in S3.
◍ What are the S3 Basics.
Answer: 1. Unlimited Storage2. Objects up to 5TB in size can be stored3.
Store files in Buckets (similar to folders)4. Universal namespace5. When
files are uploaded to an S3 bucket you receive an HTTP 200 code.
◍ You want to pull Docker images from a private ECR repository. Which
AWS CLI command can you use? (Udemy).
Answer: aws ecr get-login-password --region $AWS_REGION | docker
login --username AWS --password-stdin $ECR_URLdocker pull
$ECR_IMAGE_URL
◍ Registered targets in a Target Groups for an Application Load Balancer can
be one of the following, EXCEPT: (Udemy).
Answer: Network Load Balancer
◍ You would like to deploy a database technology on an EC2 instance and the
vendor license bills you based on the physical cores and underlying network
socket visibility. Which EC2 Purchasing Option allows you to get visibility
into them? (Udemy).
, Answer: Dedicated Hosts
◍ What is an API Gateway 1.
Answer: 1. Publish Maintain, and Monitor APIs: API Gateway is a service
which allows you to publish, maintain, monitor, and secure APIs at any
scale. 2. A Front Door: An API is like a front door for applications to access
data, business login, or functionality from your backend services, e.g.,
applications running on EC2, Lambda. 3. Supported API Types - RESTful
APIs are optimized for stateless, serverless workloads. - Websocket APIs
are for real-time, two-way, stateful communication e.g. chat apps.
◍ You're hosting a dynamic website fronted by an ElastiCache Cluster. You
have been instructed to keep latency to a minimum for all read requests for
every user. Also, writes can take longer to happen. Which caching strategy
do you recommend?.
Answer: Write Through
◍ What is CMK.
Answer: Customer Master KeyEncrypting/ decrypting data up to 4KBUsed
for generating / encrypting / decrypting the Data Key. Data Key is then used
to encrypt/ decrypt your data
◍ What are the properties of Dedicated Instances/ Hosts.
Answer: Compliance: Regulatory requirements that may not support
multi-tenant virtualizationLicensing: Great for licensing which does not
support multi-tenancy or cloud deploymentsOn-Demand: Can be purchased
on-demand (hourly)Reserved: Can be purchased as a reservation for up to
70% off the on-demand price.
◍ What does this S3 bucket policy do?{"Version": "2012-10-17","Id":
"Mystery policy","Statement": [{"Sid": "What could it be?","Effect":
"Allow","Principal": {"Service": "cloudfront.amazonaws.com"},"Action":
"s3:GetObject","Resource": "arn:aws:s3:::examplebucket/*","Condition":
{"StringEquals": {"AWS:SourceArn":
"arn:aws:cloudfront::123456789012:distribution/EDFDVBD6EXAMPLE"}}}]}
(Udemy).
, Answer: Only allows the S3 bucket content to be accessed from your
CloudFront Distribution
◍ Your administrator launched a Linux EC2 instance and gives you the EC2
Key Pair so you can SSH into it. After getting into the EC2 instance, you
want to get the EC2 instance ID. What is the best way to do this? (Udemy).
Answer: Query the metadata at http://169.254.169.254/latest/meta-data
◍ What are Athena Use Cases.
Answer: Query (log files): Query log files stored in S3 e.g. ELB logs, S3
access logs, etc. Perform (Cost analysis): Analyze AWS Cost and usage
reportsGenerate (Business report): Generate business report on data stored
in S3. Analyze (Click-stream): Run queries on click-stream data.
◍ You have updated a Route 53 Record's myapp.mydomain.com value to
point to a new Elastic Load Balancer, but it looks like users are still
redirected to the old ELB. What is a possible cause for this behavior?
(Udemy).
Answer: Because of the TTL
◍ What is wrong with the following CloudFormation
template?Mappings:AWSRegionArch2AMI:us-east-1:HVM64:
ami-6869aa05us-west-2:HVM64: ami-7172b611us-west-1:HVM64:
ami-31490d51eu-west-1:HVM64:
ami-f9dd458aEnvironmentToInstanceType:development:instanceType:
t2.microproduction:instanceType: m4.largeResources:EC2Instance:Type:
AWS::EC2::InstanceProperties:InstanceType: !FindInMap
[EnvironmentToInstanceType, !Ref 'EnvironmentName',
instanceType]ImageId: !FindInMap [AWSRegionArch2AMI, !Ref
'AWS::Region', HVM64] (Udemy).
Answer: The parameter EnvironmentName is missing
◍ What is MemoryDB for Redis.
Answer: Massively Scalable: In-memory database (GB to >100 TB)Highly
Available: Multi A-Z. Transaction log for recovery and durabilityPrimary
Database: The entire dataset for an application can be stored in memory
, (instead of database plus a cache). Ultra-Fast Performance: Supports > 160
million requests per second. Microsecond read and single-digit millisecond
write latency.
◍ What are Restful APIs.
Answer: - Representational State Transfer- Optimized for serverless and
web applications. - Stateless. - Supports JSON JavaScript Object Notation. -
JSON uses key-value pairs.
◍ What is DynamoDB streams.
Answer: Time Ordered Sequence of item level modification(e.g. insert,
update, delete)Logs are encrypted at rest and stored for 24 hoursAccessed
using a dedicated endpoint.By default primary key is recorded.Before and
after images can be capturedUsed cases: Audit or archive transactions,
trigger an event based on a particular transaction, or replicate data across
multiple tables. Very good for Lambda Event Source therefore creating
application that take actions based on events in users DynamoDB table.
◍ Why does API Gateway use Throttling.
Answer: To prevent your API from being overwhelmed by too many
requests. Default Limits: 10,000 requests per seconds (rps) and 5,000
concurrent requests. If exceeded the limit, API Gateway will return an error:
429, Too Many Requests.
◍ Which of the following is NOT a Glacier Flexible retrieval mode? (Udemy).
Answer: Instant (10 seconds)
◍ You have 3 different applications that you'd like to send them the same
message. All 3 applications are using SQS. What is the best approach would
you choose? (Udemy).
Answer: Use SNS + SQS Fan Out Pattern
◍ What are the properties of On-Demand Instances.
Answer: 1. Flexible: Low cost and flexibility of Amazon EC2 without and
up-front payment or long-term commitment. 2. Short-Term: Application
with short -term, spiky or unpredictable workloads that cannot be
CERTIFICATION SCRIPT 2026 QUESTIONS
WITH SOLUTIONS GRADED A+
◍ What are the type of Primary Keys for DynamoDB.
Answer: Partition KeyPartition key based on a unique attribute. Composite
key is a combination of (partition key + sort key). It is used when partition
key is not unique. sort key can be a timestamp
◍ What Athena.
Answer: Its an Interactive query service.Enables user to run standard SQL
queries on data stored in S3.
◍ What are the S3 Basics.
Answer: 1. Unlimited Storage2. Objects up to 5TB in size can be stored3.
Store files in Buckets (similar to folders)4. Universal namespace5. When
files are uploaded to an S3 bucket you receive an HTTP 200 code.
◍ You want to pull Docker images from a private ECR repository. Which
AWS CLI command can you use? (Udemy).
Answer: aws ecr get-login-password --region $AWS_REGION | docker
login --username AWS --password-stdin $ECR_URLdocker pull
$ECR_IMAGE_URL
◍ Registered targets in a Target Groups for an Application Load Balancer can
be one of the following, EXCEPT: (Udemy).
Answer: Network Load Balancer
◍ You would like to deploy a database technology on an EC2 instance and the
vendor license bills you based on the physical cores and underlying network
socket visibility. Which EC2 Purchasing Option allows you to get visibility
into them? (Udemy).
, Answer: Dedicated Hosts
◍ What is an API Gateway 1.
Answer: 1. Publish Maintain, and Monitor APIs: API Gateway is a service
which allows you to publish, maintain, monitor, and secure APIs at any
scale. 2. A Front Door: An API is like a front door for applications to access
data, business login, or functionality from your backend services, e.g.,
applications running on EC2, Lambda. 3. Supported API Types - RESTful
APIs are optimized for stateless, serverless workloads. - Websocket APIs
are for real-time, two-way, stateful communication e.g. chat apps.
◍ You're hosting a dynamic website fronted by an ElastiCache Cluster. You
have been instructed to keep latency to a minimum for all read requests for
every user. Also, writes can take longer to happen. Which caching strategy
do you recommend?.
Answer: Write Through
◍ What is CMK.
Answer: Customer Master KeyEncrypting/ decrypting data up to 4KBUsed
for generating / encrypting / decrypting the Data Key. Data Key is then used
to encrypt/ decrypt your data
◍ What are the properties of Dedicated Instances/ Hosts.
Answer: Compliance: Regulatory requirements that may not support
multi-tenant virtualizationLicensing: Great for licensing which does not
support multi-tenancy or cloud deploymentsOn-Demand: Can be purchased
on-demand (hourly)Reserved: Can be purchased as a reservation for up to
70% off the on-demand price.
◍ What does this S3 bucket policy do?{"Version": "2012-10-17","Id":
"Mystery policy","Statement": [{"Sid": "What could it be?","Effect":
"Allow","Principal": {"Service": "cloudfront.amazonaws.com"},"Action":
"s3:GetObject","Resource": "arn:aws:s3:::examplebucket/*","Condition":
{"StringEquals": {"AWS:SourceArn":
"arn:aws:cloudfront::123456789012:distribution/EDFDVBD6EXAMPLE"}}}]}
(Udemy).
, Answer: Only allows the S3 bucket content to be accessed from your
CloudFront Distribution
◍ Your administrator launched a Linux EC2 instance and gives you the EC2
Key Pair so you can SSH into it. After getting into the EC2 instance, you
want to get the EC2 instance ID. What is the best way to do this? (Udemy).
Answer: Query the metadata at http://169.254.169.254/latest/meta-data
◍ What are Athena Use Cases.
Answer: Query (log files): Query log files stored in S3 e.g. ELB logs, S3
access logs, etc. Perform (Cost analysis): Analyze AWS Cost and usage
reportsGenerate (Business report): Generate business report on data stored
in S3. Analyze (Click-stream): Run queries on click-stream data.
◍ You have updated a Route 53 Record's myapp.mydomain.com value to
point to a new Elastic Load Balancer, but it looks like users are still
redirected to the old ELB. What is a possible cause for this behavior?
(Udemy).
Answer: Because of the TTL
◍ What is wrong with the following CloudFormation
template?Mappings:AWSRegionArch2AMI:us-east-1:HVM64:
ami-6869aa05us-west-2:HVM64: ami-7172b611us-west-1:HVM64:
ami-31490d51eu-west-1:HVM64:
ami-f9dd458aEnvironmentToInstanceType:development:instanceType:
t2.microproduction:instanceType: m4.largeResources:EC2Instance:Type:
AWS::EC2::InstanceProperties:InstanceType: !FindInMap
[EnvironmentToInstanceType, !Ref 'EnvironmentName',
instanceType]ImageId: !FindInMap [AWSRegionArch2AMI, !Ref
'AWS::Region', HVM64] (Udemy).
Answer: The parameter EnvironmentName is missing
◍ What is MemoryDB for Redis.
Answer: Massively Scalable: In-memory database (GB to >100 TB)Highly
Available: Multi A-Z. Transaction log for recovery and durabilityPrimary
Database: The entire dataset for an application can be stored in memory
, (instead of database plus a cache). Ultra-Fast Performance: Supports > 160
million requests per second. Microsecond read and single-digit millisecond
write latency.
◍ What are Restful APIs.
Answer: - Representational State Transfer- Optimized for serverless and
web applications. - Stateless. - Supports JSON JavaScript Object Notation. -
JSON uses key-value pairs.
◍ What is DynamoDB streams.
Answer: Time Ordered Sequence of item level modification(e.g. insert,
update, delete)Logs are encrypted at rest and stored for 24 hoursAccessed
using a dedicated endpoint.By default primary key is recorded.Before and
after images can be capturedUsed cases: Audit or archive transactions,
trigger an event based on a particular transaction, or replicate data across
multiple tables. Very good for Lambda Event Source therefore creating
application that take actions based on events in users DynamoDB table.
◍ Why does API Gateway use Throttling.
Answer: To prevent your API from being overwhelmed by too many
requests. Default Limits: 10,000 requests per seconds (rps) and 5,000
concurrent requests. If exceeded the limit, API Gateway will return an error:
429, Too Many Requests.
◍ Which of the following is NOT a Glacier Flexible retrieval mode? (Udemy).
Answer: Instant (10 seconds)
◍ You have 3 different applications that you'd like to send them the same
message. All 3 applications are using SQS. What is the best approach would
you choose? (Udemy).
Answer: Use SNS + SQS Fan Out Pattern
◍ What are the properties of On-Demand Instances.
Answer: 1. Flexible: Low cost and flexibility of Amazon EC2 without and
up-front payment or long-term commitment. 2. Short-Term: Application
with short -term, spiky or unpredictable workloads that cannot be
