Pass the Amazon Web Services AWS Certified Associate MLA-C01 Questions and answers with CertsForce

Option D is correct because the company’s primary goal is to identify as many fraudulent transactions as possible. In AWS documentation, recall is defined as TP / (TP + FN), where TP is true positives and FN is false negatives. Recall measures how well a model finds all actual positive cases. In a fraud-detection setting, the “positive” class is the fraudulent transaction, so maximizing recall means minimizing missed fraud cases.

AWS documentation also explains the business tradeoff clearly: a use case that needs to correctly predict as many positive examples as possible should prioritize high recall, even if that means accepting some additional false positives and therefore only moderate precision. That matches this question exactly, because the requirement is not to be most selective or most balanced overall; it is specifically to catch the largest possible number of fraudulent transactions.

The other metrics are less aligned to the stated goal. Precision focuses on how many predicted fraud cases are actually fraud, which is most important when false positives are very costly. F1 score balances precision and recall, but the question does not ask for balance; it asks for finding as many fraudulent transactions as possible. AUC is useful for overall ranking and threshold-independent model discrimination, but it is not the most direct metric for optimizing missed-fraud detection in this scenario. Based on AWS metric definitions, when the cost of missing true positives is the main concern, recall is the best evaluation metric. Therefore, the best verified answer is D.

Amazon SageMaker AI shadow testing enables ML engineers to evaluate new model versions by sending a copy of live production traffic to a shadow variant without affecting production inference responses. AWS documentation specifies that shadow variants are configured separately from production variants and can use different instance types, including higher-performance GPU instances.

The correct approach is to create a new endpoint configuration using the CreateEndpointConfig API. This configuration includes the existing production variant and a separate ShadowProductionVariants list. The shadow variant can be assigned a larger instance type to meet GPU performance requirements while leaving the production variant unchanged. After creating the configuration, the engineer deploys it using the CreateEndpoint action.

Option A is incorrect because production variant configurations cannot be directly modified to include shadow variants. Option B is incorrect because shadow variants are not defined as standard production variants; defining two production variants would route traffic differently and could affect production behavior. Option C introduces unnecessary complexity and deviates from SageMaker’s built-in shadow testing functionality.

AWS explicitly documents that shadow variants are designed to isolate testing resources, support different instance types, and ensure zero impact on production inference. Therefore, Option D is the correct and AWS-recommended solution.

This dataset shows severe class imbalance, with only 2% of records representing patients with the disease. AWS ML best practices recommend correcting imbalance only in the training dataset, while keeping validation and test sets representative of real-world distributions.

Synthetic Minority Oversampling Technique (SMOTE) generates synthetic samples of the minority class by interpolating between existing minority examples. This improves the model’s ability to learn disease-related patterns without discarding data.

PCA is a dimensionality reduction method, not an oversampling technique. Oversampling the majority class worsens imbalance. Altering the test dataset would invalidate evaluation results.

Therefore, applying SMOTE to the training dataset is the correct approach.

Step 1:

The company commits code changes or new training datasets to a Git repository.

This is the trigger point. A source code or data change initiates the CI/CD pipeline.

Step 2:

CodePipeline detects code changes and starts to build automatically.

CodePipeline monitors the Git repository (for example, AWS CodeCommit, GitHub, or Bitbucket) and automatically triggers the pipeline when changes are detected.

Step 3:

The company builds and deploys ML models and applications to staging servers for testing.

The pipeline runs build, training, and test stages (often using AWS CodeBuild and SageMaker) and deploys artifacts to a staging or test environment for validation.

Step 4:

Human approval is provided after testing is successful.

A manual approval action is a best practice for ML workflows to ensure governance, compliance, and quality checks before production deployment.

Step 5:

CodePipeline deploys ML models and applications to production.

After approval, the pipeline automatically deploys the validated model or application to the production environment.

Change the number of samples used in each iteration of training

Correct selection:

Change the batch size

Why:

Increasing the batch size reduces the number of iterations per epoch, which can significantly shorten training time while maintaining model quality when tuned appropriately. AWS explicitly recommends batch size tuning as a primary performance optimization.

Increase the number of instances used during training

Correct selection:

Use the SageMaker AI distributed data parallelism (SMDDP) library

Why:

SMDDP is designed to efficiently distribute training data across multiple GPU instances with optimized gradient synchronization. This accelerates training without affecting model convergence or accuracy, unlike naive scaling approaches.

Stop training before the maximum number of epochs are reached if performance is sufficient and not improving

Correct selection:

Use early stopping on the training job

Why:

Early stopping automatically terminates training when validation metrics stop improving. AWS recommends this to reduce wasted compute time while preserving optimal model performance.

In regression problems such as house price prediction, extreme values can significantly distort model learning. In this dataset, the presence of a large mansion and an extremely small apartment represents clear outliers in the Square Meters feature. According to AWS Machine Learning best practices, outliers can disproportionately influence loss functions (such as mean squared error), leading to poor predictions for the majority of typical data points.

Removing these outliers helps the model focus on learning patterns that apply to the majority of houses and apartments, which aligns with the requirement to produce accurate predictions for typical properties. After removing outliers, applying a log transformation to the Square Meters feature further improves model performance by reducing skewness and stabilizing variance. Log transformations are commonly recommended in AWS and general ML documentation when numerical features span multiple orders of magnitude.

Option B is incorrect because normalization alone does not address the undue influence of extreme outliers. Option C and D are incorrect because one-hot encoding is intended for categorical variables, not continuous numerical features such as square meters.

Therefore, removing outliers and applying a log transformation is the most statistically sound preprocessing approach.

Option C is correct because the company needs Kubernetes hosting, does not want to manage the control plane, wants repeatable infrastructure provisioning, and requires that provisioning be done by using Python. Amazon EKS is AWS’s managed Kubernetes service, so it satisfies the requirement to avoid managing the Kubernetes control plane directly. The AWS CDK documentation also confirms that Python is a fully supported client language for defining infrastructure as code.

AWS CDK is the best fit because it lets engineers define cloud infrastructure programmatically in Python and deploy it in a repeatable way. The AWS CDK EKS construct library specifically supports defining Amazon EKS clusters and related Kubernetes resources. This makes it a strong match for infrastructure that must be reproducible and expressed in code rather than provisioned manually. Since the model is already packaged in a container, storing the image in Amazon ECR and then deploying it to Amazon EKS follows the normal AWS container workflow.

The other options are less suitable. Option A requires setting up and managing a Kubernetes cluster on EC2, which violates the requirement to avoid control-plane management. Option B uses the AWS CLI, but the question specifically requires infrastructure provisioning by using Python, not command-line provisioning. Option D uses CloudFormation, which is repeatable infrastructure as code, but the question explicitly says the infrastructure must be provisioned by using Python. AWS CDK uniquely satisfies both the IaC and Python requirements while using managed Kubernetes with EKS.

Therefore, the best verified AWS-docs answer is C.

Option A is correct because Amazon SageMaker Feature Store is the AWS service designed to act as a centralized repository for ML features that are used consistently across training and inference. AWS documentation states that SageMaker Feature Store simplifies how you create, store, share, and manage features for data exploration, model training, and model inference. This directly matches the requirement to create a repository for streamed song ratings that will be used in both batch training and real-time inference.

The most important requirement in the question is that the data must stay synchronized between batch training and real-time inference. AWS documents explain that Feature Store provides both an offline store and an online store. The offline store is used for historical data, model training, and batch inference, while the online store is a low-latency, high-availability store intended for real-time lookup during inference. This dual-store design is exactly why Feature Store is used to maintain feature consistency across training and serving workflows. AWS Well-Architected guidance also explicitly says Feature Store provides online storage for real-time inference and offline storage for model training and batch inference.

The other options do not solve the full problem. Athena CTAS can organize query results but does not provide a synchronized feature repository for online and offline ML use. Lake Formation governs access to data lakes but is not a feature repository for training and inference consistency. Data Wrangler Generate Data Insights is for analysis and preparation, not synchronized feature serving. Therefore, the best AWS-documented answer is A.

AWS Secrets Manager is designed for securely storing, managing, and automatically rotating secrets, including API tokens. By configuring a Lambda function for custom rotation logic, the solution can automatically rotate the API tokens every 3 months as required. Secrets Manager simplifies secret management and integrates seamlessly with other AWS services, making it the ideal choice for this use case.

The described behavior indicates overfitting, where the model starts to memorize training data instead of generalizing.

Early stopping halts training when validation performance stops improving, preventing the model from overfitting further. AWS documentation recommends early stopping as a primary regularization technique.

Dropout randomly disables neurons during training, forcing the model to learn robust representations and reducing reliance on specific neurons. Increasing dropout is a well-established method for improving generalization.

Increasing layers or neurons increases model capacity and worsens overfitting. Model bias is unrelated to epoch-based degradation.

Therefore, Options A and B are correct.