MLA-C01 Practice Exam 2 — 20 Questions

Question 1

A data science team is using Amazon SageMaker Pipelines to orchestrate a multi-step workflow that includes data preprocessing, training, and model evaluation. They want to reuse the preprocessed data across multiple pipeline executions without re-running the preprocessing step if the source data hasn't changed. What should they configure?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Use SageMaker Processing steps with caching. SageMaker Processing steps support caching, which allows the pipeline to skip re-execution of the preprocessing step if the input data and pipeline parameters have not changed. This is achieved by configuring a `CacheConfig` with a caching key based on the input data source and step parameters, ensuring that the preprocessed data is reused across multiple pipeline executions without redundant computation.

Answer

Use SageMaker Training steps with checkpointing

Answer

Use SageMaker Feature Store to store the preprocessed features

Answer

Use SageMaker Data Wrangler for the preprocessing

Question 2

A data science team deploys a real-time inference endpoint on Amazon SageMaker. They want to monitor for data drift in the input features over time. Which AWS service should they use to capture and analyze the input data distribution?

Accepted Answer

Amazon SageMaker Model Monitor. Amazon SageMaker Model Monitor is the correct service because it is specifically designed to continuously monitor machine learning models in production for data drift and quality issues. It automatically captures input data distributions from real-time inference endpoints and compares them against a baseline to detect statistical changes, alerting the team when drift occurs.

Answer

Amazon Athena

Answer

AWS CloudTrail

Answer

Amazon CloudWatch Logs

Question 3

A data scientist is using SageMaker Data Wrangler to prepare a large dataset. The data contains duplicate rows, which could bias the model. Which built-in step in Data Wrangler can automatically detect and remove duplicates?

Accepted Answer

Handle Duplicates transform in Data Wrangler. The Handle Duplicates transform is a built-in step in SageMaker Data Wrangler specifically designed to detect and remove duplicate rows from a dataset. It provides configurable options such as selecting a subset of columns for duplicate detection and choosing whether to keep the first or last occurrence, directly addressing the bias risk from duplicate rows in ML training data.

Answer

Amazon QuickSight duplicate detection

Answer

AWS Glue Studio FindDuplicates transform

Answer

Amazon DataZone catalog

Question 4

A machine learning engineer is using Amazon SageMaker Experiments to track multiple training runs. They want to compare the performance of different hyperparameter configurations visually. Which SageMaker tool provides an interactive interface to compare experiments?

Accepted Answer

SageMaker Studio. SageMaker Studio provides an interactive, web-based interface that allows you to visually compare experiment runs, including hyperparameter configurations and performance metrics, through built-in experiment management and visualization tools. This is the correct answer because the question specifically asks for an interactive interface, which Studio offers natively, unlike the other options which are programmatic or monitoring-focused.

Answer

SageMaker Model Monitor

Answer

SageMaker Experiments SDK

Answer

SageMaker Debugger Insights

Question 5

A company uses SageMaker endpoints with auto-scaling. The endpoint is experiencing high latency during peak hours. The metrics show CPU utilization is low but memory is high. What is the most likely cause?

Accepted Answer

The auto-scaling policy is based on CPU utilization, which does not trigger scaling.. The auto-scaling policy is based on CPU utilization, which remains low during the memory-bound issue. Since the scaling trigger is not met, the endpoint does not add more instances to handle the increased load, leading to high latency. Memory pressure without CPU spikes indicates the bottleneck is memory, not compute, so a CPU-based metric fails to scale appropriately.

Answer

The model is not optimized for inference, causing memory leaks.

Answer

The instance type has insufficient network bandwidth.

Answer

The endpoint is deployed in a VPC without a NAT gateway.

Question 6

A company deploys a machine learning model as a SageMaker real-time endpoint. They need to implement a mechanism to automatically roll back to the previous model version if performance degrades after a deployment. Which approach should they use?

Accepted Answer

Configure the SageMaker endpoint deployment with traffic shifting and set up CloudWatch alarms to trigger automatic rollback. SageMaker endpoints support deployment with traffic shifting (e.g., canary or linear patterns) via the 'DeploymentConfig' parameter, and you can attach CloudWatch alarms to the endpoint's variant metrics. If the alarm triggers (e.g., due to increased error rate or latency), SageMaker automatically rolls back the traffic to the previous model version, ensuring minimal manual intervention and fast recovery.

Answer

Manually update the endpoint to point to the previous model version

Answer

Create multiple endpoints and use Amazon Route 53 weighted routing to shift traffic

Answer

Use AWS CodeDeploy with Amazon EC2 instances behind an Elastic Load Balancer

Question 7

A machine learning team deploys a custom container image for an Amazon SageMaker training job. The container needs to access an S3 bucket that contains sensitive data. The team wants to follow the principle of least privilege. How should the team grant access?

Accepted Answer

Create an IAM role with S3 access and assign it as the SageMaker execution role for the training job.. SageMaker training jobs use an IAM execution role to grant permissions to AWS services like S3. By creating a dedicated IAM role with only the necessary S3 actions (e.g., s3:GetObject, s3:PutObject) and assigning it as the SageMaker execution role, the team follows the principle of least privilege. SageMaker automatically assumes this role via AWS Security Token Service (STS) to access the S3 bucket on behalf of the container, without embedding credentials.

Answer

Attach an IAM instance profile to the training instance with permissions to the bucket.

Answer

Configure an S3 bucket policy that grants access to the training job's ARN.

Answer

Store AWS access keys in the container image and use them to access the bucket.

Question 8

Refer to the exhibit. A user has the above IAM policy attached but cannot access files in SageMaker Studio. What additional permission is most likely needed?

Accepted Answer

s3:GetObject on the relevant S3 buckets. The IAM policy shown likely grants permissions for SageMaker API actions (e.g., CreateApp, DescribeDomain) but does not include S3 data plane permissions. SageMaker Studio notebooks and experiments read training data, scripts, and model artifacts from S3 buckets. Without s3:GetObject on the relevant S3 buckets, the user can launch the Studio environment but cannot load or save any files, resulting in access failures.

Answer

sagemaker:ListApps

Answer

sagemaker:DescribeUserProfile

Answer

kms:Decrypt

Question 9

A data scientist trained a model using SageMaker and wants to automate the retraining process when new data becomes available. Which AWS service is best suited to trigger a SageMaker training job based on an S3 event?

Accepted Answer

Amazon EventBridge with a rule matching S3 object creation.. Amazon EventBridge is the correct choice because it can directly capture S3 events (such as ObjectCreated) via a rule and invoke a SageMaker training job as a target. This event-driven architecture eliminates the need for polling or scheduled checks, enabling immediate retraining when new data arrives in S3.

Answer

AWS Step Functions with a scheduled trigger.

Answer

Amazon Simple Workflow Service (SWF) decider.

Answer

Amazon Simple Queue Service (SQS) with a polling script.

Question 10

A company has a batch transform job in Amazon SageMaker that processes large datasets every night. Recently, the job has been failing sporadically with an out-of-memory error. The data size has not increased. What is the MOST likely cause?

Accepted Answer

The custom inference code has a memory leak that gradually consumes available memory.. A memory leak in custom inference code would cause gradual memory consumption over time, eventually leading to out-of-memory errors even if the dataset size remains unchanged. SageMaker batch transform jobs run inference on each record independently, so a leak that accumulates across records (e.g., not releasing tensors or file handles) would cause sporadic failures as the job processes more data.

Answer

The data distribution has shifted, causing different memory usage patterns.

Answer

The instance type is not large enough to handle the dataset.

Answer

The batch transform input data has increased in size.

Question 11

A machine learning team trains a model in SageMaker and wants to track every step — from dataset version to hyperparameters to final model artifact — for reproducibility and audit compliance. Which SageMaker feature should they use?

Accepted Answer

SageMaker ML Lineage Tracking. SageMaker ML Lineage Tracking is the correct choice because it is specifically designed to create a directed acyclic graph (DAG) of every step in the ML workflow, including dataset versions, hyperparameters, training jobs, and model artifacts. This enables full reproducibility and audit compliance by capturing the provenance of each entity and their relationships, which is exactly what the question requires.

Answer

SageMaker Feature Store

Answer

SageMaker Experiments

Answer

SageMaker Model Registry

Question 12

A financial services company needs to deploy a machine learning model for real-time fraud detection. The model must be highly available across multiple Availability Zones and must support automatic scaling based on request volume. The company also needs to perform canary deployments to test new model versions with a small percentage of traffic before full rollout. Which SageMaker feature should they use?

Accepted Answer

SageMaker real-time endpoint with production variants. SageMaker real-time endpoints with production variants enable canary deployments by routing a small percentage of traffic to a new model version while the majority goes to the current version. This feature also supports multi-AZ deployment for high availability and automatic scaling based on request volume via Application Auto Scaling, meeting all the stated requirements.

Answer

SageMaker Multi-Model Endpoint

Answer

SageMaker Batch Transform

Answer

SageMaker Serverless Inference

Question 13

A data science team has trained a PyTorch model for real-time inference and needs to deploy it on AWS with GPU acceleration while minimizing cold-start latency. Which SageMaker inference option should they choose?

Accepted Answer

Real-time endpoint with ml.g4dn instance. Real-time endpoints with GPU instances (e.g., ml.g4dn) provide low latency and support GPU acceleration, suitable for interactive inference. Serverless inference does not support GPU instances, asynchronous inference is for non-real-time, and batch transform is for offline predictions.

Answer

Serverless inference

Answer

Batch transform

Answer

Asynchronous inference endpoint

Question 14

A financial services firm is training a fraud detection model using SageMaker. The dataset is highly imbalanced (0.1% fraudulent transactions). The model currently achieves 99.9% accuracy but only catches 5% of fraud cases. Which metric should the team prioritize to evaluate model performance?

Accepted Answer

Recall. Recall is the proportion of actual fraud cases that the model correctly identifies, so it directly measures the model's ability to catch fraud. With only 5% of fraud cases caught, recall is extremely low, and improving it is the priority. Accuracy is misleading here because a model that predicts 'not fraud' for every transaction would still achieve 99.9% accuracy on a 0.1% fraud dataset.

Answer

Accuracy

Answer

Precision

Answer

F1-score

Question 15

A machine learning team needs to deploy a model that was built using scikit-learn. They want to use SageMaker for hosting. Which approach should they take?

Accepted Answer

Package the model artifacts and use the SageMaker built-in scikit-learn container for inference. SageMaker provides a pre-built, optimized Docker container for scikit-learn that supports inference. By packaging the model artifacts (e.g., a joblib or pickle file) and deploying them using the built-in container, the team avoids the overhead of custom container creation while ensuring compatibility with SageMaker's hosting infrastructure, including automatic scaling and load balancing.

Answer

Create a Jupyter notebook that loads the model and runs predictions on the SageMaker notebook instance

Answer

Create a custom Docker container with scikit-learn and deploy it on SageMaker

Answer

Launch a SageMaker training job with the model and use the training instance as an endpoint

Question 16

A data scientist is training a binary classifier on a highly imbalanced dataset (1:100 class ratio). The dataset contains 500,000 rows and 30 features. The data is stored in S3 in Parquet format. The data scientist wants to use SageMaker's built-in XGBoost algorithm. Which data preparation technique should the data scientist apply to best address the class imbalance without causing data leakage?

Accepted Answer

Use the scale_pos_weight parameter in XGBoost to assign higher weight to the minority class.. The scale_pos_weight parameter in XGBoost directly adjusts the loss function to penalize misclassifications of the minority class more heavily, effectively handling class imbalance without modifying the dataset. This avoids data leakage because the weighting is applied during training only, not during preprocessing, and does not involve any synthetic data generation or resampling that could inadvertently expose test information.

Answer

Undersample the majority class to create a balanced dataset, then split.

Answer

Oversample the minority class using SMOTE on the entire dataset before splitting into train/validation sets.

Answer

Randomly oversample the minority class by duplicating rows, then perform stratified train/test split.

Question 17

A healthcare company is building a model to predict patient readmission rates. The dataset contains a mix of numeric features (age, blood pressure, lab test results) and categorical features (gender, diagnosis code, hospital department). The dataset has 2 million rows. The data is stored in an Amazon S3 bucket, and they use AWS Glue to catalog and preprocess the data. The data scientist notices that the 'diagnosis_code' column has 10,000 unique codes, and 20% of the rows have missing values for 'blood_pressure'. They plan to use a SageMaker built-in XGBoost model. For optimal model performance, which preprocessing steps should they apply using AWS Glue ETL?

Accepted Answer

Impute missing 'blood_pressure' with median, and apply integer encoding to 'diagnosis_code'.. XGBoost handles missing values natively, so median imputation for 'blood_pressure' is robust to outliers and preserves data distribution, while integer encoding (label encoding) for 'diagnosis_code' with 10,000 unique values is efficient and avoids the dimensionality explosion of one-hot encoding. AWS Glue ETL can apply these transformations using built-in functions like `Imputer` and `StringIndexer` without excessive memory overhead.

Answer

Impute missing 'blood_pressure' with the mean, and apply label encoding to 'diagnosis_code'.

Answer

Replace missing 'blood_pressure' with -1 and apply one-hot encoding to 'diagnosis_code' after grouping rare codes into 'other'.

Answer

Apply one-hot encoding to 'diagnosis_code' and drop rows with missing 'blood_pressure'.

Question 18

A company has deployed a machine learning model on Amazon SageMaker and wants to automatically detect when the distribution of input features deviates significantly from the training data distribution. Which SageMaker feature should they use?

Accepted Answer

SageMaker Model Monitor – Data Quality Monitoring. SageMaker Model Monitor – Data Quality Monitoring is the correct choice because it is specifically designed to detect deviations in the distribution of input features compared to the training data distribution. It continuously monitors incoming inference requests and compares statistical properties (e.g., mean, variance, or histogram) against a baseline computed from the training dataset, alerting when drift is detected.

Answer

SageMaker Clarify

Answer

SageMaker Edge Manager

Answer

SageMaker Model Monitor – Model Quality Monitoring

Question 19

A data engineer is building a data pipeline for a machine learning model that requires both structured and unstructured data. The structured data (customer demographics) is in Amazon RDS, and the unstructured data (customer support chat logs) is in Amazon S3 as JSON files. The engineer needs to combine these datasets into a single training dataset stored in S3 in Parquet format. They must also perform feature engineering such as text vectorization on the chat logs. The pipeline should be serverless and cost-effective. Which approach should they use?

Accepted Answer

Use AWS Glue ETL with a Spark script that reads from RDS (via JDBC) and S3, performs transformations, and writes Parquet.. AWS Glue ETL with a Spark script is the correct choice because it natively supports reading from both Amazon RDS (via JDBC) and Amazon S3 (JSON), performing complex transformations like text vectorization, and writing the output as Parquet. Glue is serverless, cost-effective (pay per DPU-hour), and fully managed, making it ideal for batch ETL pipelines that combine structured and unstructured data for ML training.

Answer

Use a SageMaker Processing job with a custom Python script that reads from both sources and writes to S3.

Answer

Use Amazon Athena to join the data from RDS and S3, then export the results as Parquet.

Answer

Use Amazon Kinesis Data Analytics to read from RDS and S3 and produce a continuous stream of processed data.

Question 20

A data science team uses Amazon SageMaker Model Monitor to detect data drift in production. They notice that the schema of incoming data (number of features) has changed compared to the training baseline. Which type of monitor is BEST suited to detect this issue?

Accepted Answer

Data quality monitor. The Data quality monitor in SageMaker Model Monitor is specifically designed to detect violations in the input data schema, such as changes in the number of features, feature types, or missing values, by comparing incoming data against a baseline computed from the training dataset. Since the issue is a structural change in the schema (number of features), the Data quality monitor is the correct choice.

Answer

Bias drift monitor

Answer

Feature attribution drift monitor

Answer

Model quality monitor