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200+ Free AWS Machine Learning Specialty Practice Questions

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A data science team needs to store large-scale training datasets that will be accessed by multiple SageMaker training jobs running in different Availability Zones. The data must be durable, highly available, and accessible via standard file system interfaces. Which storage solution should they use?

A
B
C
D
to track
2026 Statistics

Key Facts: AWS Machine Learning Specialty Exam

~55-65%

Estimated Pass Rate

Industry estimate

750/1000

Passing Score

AWS

100-150 hrs

Study Time

Recommended

2+ years

AWS Experience

Recommended

65

Total Questions

50 scored + 15 unscored

$300

Exam Fee

AWS

The AWS Machine Learning Specialty (MLS-C01) requires a scaled score of 750/1000 to pass. The exam has 65 questions (50 scored + 15 unscored) in 180 minutes. Domain 3 (Modeling) is the largest at 36%, followed by Domain 2 (EDA) at 24%, Domain 1 (Data Engineering) at 20%, and Domain 4 (ML Ops) at 20%. AWS recommends 2+ years of hands-on ML experience. The exam fee is $300.

Sample AWS Machine Learning Specialty Practice Questions

Try these sample questions to test your AWS Machine Learning Specialty exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 200+ question experience with AI tutoring.

1A data science team needs to store large-scale training datasets that will be accessed by multiple SageMaker training jobs running in different Availability Zones. The data must be durable, highly available, and accessible via standard file system interfaces. Which storage solution should they use?
A.Amazon S3 with Transfer Acceleration
B.Amazon EFS (Elastic File System)
C.Amazon EBS gp3 volumes attached to each instance
D.Amazon FSx for Lustre
Explanation: Amazon EFS provides a managed NFS service that allows multiple instances across different AZs to mount and access the same file system concurrently. EFS is ideal for ML training scenarios where multiple nodes need shared access to datasets. S3 is object storage and does not provide a native file system interface. EBS volumes can only attach to one instance at a time. FSx for Lustre is optimized for high-performance computing and can be more expensive for general-purpose shared storage needs.
2A company needs to ingest real-time streaming data from IoT sensors for immediate ML inference. The data volume varies significantly throughout the day. Which AWS service combination is most cost-effective for this use case?
A.Amazon Kinesis Data Streams with Auto Scaling
B.Amazon Kinesis Data Firehose with Lambda transformations
C.Amazon MSK (Managed Streaming for Kafka) with Spot Instances
D.Amazon SQS with EC2 Auto Scaling groups
Explanation: Amazon Kinesis Data Firehose is a fully managed service that automatically scales to match throughput and can invoke Lambda functions for real-time data transformation before delivery to destinations like S3 or Redshift. It is serverless and cost-effective for variable workloads. Kinesis Data Streams requires manual shard management. MSK is overkill for simple ingestion and requires cluster management. SQS is a message queue, not a streaming service, and does not maintain message ordering or support real-time analytics as effectively.
3Which S3 storage class is most appropriate for ML training datasets that are accessed frequently for the first 30 days, then rarely accessed but must remain immediately available for occasional retraining?
A.S3 Standard throughout the lifecycle
B.S3 Intelligent-Tiering with automatic archiving
C.S3 Standard-IA after 30 days via Lifecycle Policy
D.S3 Glacier Deep Archive
Explanation: S3 Standard-IA (Infrequent Access) provides the same low latency and high throughput as S3 Standard but with lower storage cost and a retrieval fee, making it ideal for data accessed less than once a month. A lifecycle policy can automatically transition objects from Standard to Standard-IA after 30 days. S3 Standard is more expensive for infrequently accessed data. Intelligent-Tiering works but has a small monitoring cost. Glacier Deep Archive has retrieval times of 12+ hours, which is unacceptable for immediate access needs.
4A data engineering team needs to perform complex ETL operations on terabytes of data before ML training. They require support for Apache Spark and the ability to use custom libraries. Which service should they choose?
A.AWS Glue with Spark jobs
B.Amazon EMR with Spark
C.AWS Lambda with Python
D.Amazon Athena with Presto
Explanation: Amazon EMR provides a managed Hadoop/Spark environment that allows full control over the cluster configuration, custom library installation, and tuning for complex ETL workloads at scale. AWS Glue is serverless and simpler but has more limitations on customization and longer startup times for Spark jobs. Lambda has a 15-minute timeout and 10 GB memory limit, making it unsuitable for terabyte-scale processing. Athena is for querying data in place, not for complex ETL transformations.
5What is the primary advantage of using AWS Glue Data Catalog compared to a self-managed Hive Metastore?
A.It is free and has no storage costs
B.It is serverless, fully managed, and integrates with Lake Formation
C.It supports more data formats than Hive
D.It provides faster query execution
Explanation: AWS Glue Data Catalog is a fully managed, serverless metadata repository that integrates natively with AWS Lake Formation for fine-grained access control and works seamlessly with Athena, Redshift Spectrum, and EMR. It eliminates the need to provision and manage infrastructure. While storage costs are minimal, it is not free. The supported formats are similar to Hive. Query execution speed depends on the query engine, not the catalog.
6A team needs to create a data lake with multiple data sources and enforce column-level security for different analyst groups. Which AWS services should they use?
A.S3 with IAM policies only
B.Lake Formation with S3 and Glue Data Catalog
C.Redshift with workload management
D.RDS with row-level security
Explanation: AWS Lake Formation simplifies the creation of data lakes and provides centralized, fine-grained access control at the database, table, and column levels through integration with the Glue Data Catalog and S3. IAM policies alone cannot enforce column-level security. Redshift is a data warehouse, not a data lake. RDS is for transactional databases, not data lakes.
7For a batch ML inference job that processes hundreds of GB of data nightly and writes results to S3, which compute option is most cost-effective while maintaining reliability?
A.EC2 On-Demand instances with a custom scheduler
B.AWS Batch with Spot Instances
C.AWS Lambda triggered by S3 events
D.SageMaker Real-Time Inference endpoints
Explanation: AWS Batch with Spot Instances is ideal for batch processing workloads that can tolerate interruptions. It dynamically provisions compute resources, optimizes for cost using Spot pricing (up to 90% savings), and automatically retries failed jobs. On-Demand is more expensive. Lambda has execution time and memory limits. Real-time endpoints are designed for online inference, not batch processing.
8A company needs to process clickstream data in real-time for immediate personalization. The data arrives at variable rates up to 100,000 records per second during peak hours. Which architecture is most appropriate?
A.Kinesis Data Streams with multiple shards and EC2 consumers
B.Kinesis Data Firehose to S3 with Athena queries
C.SQS FIFO queues with Lambda
D.DynamoDB Streams with Lambda
Explanation: Kinesis Data Streams is designed for high-throughput, real-time streaming with the ability to scale by adding shards. It supports multiple consumers and can handle 100,000+ records per second when properly scaled. Firehose is for near-real-time delivery to storage, not for immediate processing. SQS FIFO has throughput limits (3,000 messages per second with batching). DynamoDB Streams is for database change events, not external clickstream data.
9When designing a data ingestion pipeline for ML, which factor should most influence the choice between batch and streaming processing?
A.The programming language used by the data science team
B.The latency requirements for the ML predictions
C.The availability of Spot Instances in the region
D.The size of the source database
Explanation: The choice between batch and streaming processing primarily depends on the latency requirements of the ML predictions. Real-time or near-real-time predictions require streaming, while historical analysis or periodic retraining can use batch. The programming language, Spot Instance availability, and database size are secondary considerations that can be addressed with various architectures.
10Which data format is generally most efficient for storing large-scale structured ML training data in S3 for queries with Athena?
A.CSV files with GZIP compression
B.JSON files with Snappy compression
C.Parquet files with Snappy compression
D.Avro files with no compression
Explanation: Parquet is a columnar storage format that provides efficient compression and encoding schemes, and allows Athena to scan only the required columns, significantly reducing query costs and improving performance. Snappy compression offers a good balance of compression ratio and speed. CSV is row-based and inefficient for analytical queries. JSON is verbose and slower to parse. Uncompressed Avro uses more storage and bandwidth.

About the AWS Machine Learning Specialty Exam

The AWS Certified Machine Learning – Specialty (MLS-C01) validates your ability to build, train, tune, and deploy machine learning models on AWS. It is designed for data scientists and developers who perform development or data science roles. The exam covers data engineering, exploratory data analysis, modeling, and ML implementation and operations using SageMaker, Kinesis, Glue, and other AWS ML services.

Questions

65 scored questions

Time Limit

3 hours

Passing Score

750/1000

Exam Fee

$300 (Amazon Web Services (AWS))

AWS Machine Learning Specialty Exam Content Outline

20%

Data Engineering

S3, EFS, Kinesis, Firehose, Glue, EMR, data transformation, and data lakes

24%

Exploratory Data Analysis

Data cleaning, feature engineering, normalization, visualization, and labeling

36%

Modeling

Algorithm selection, XGBoost, deep learning, hyperparameter tuning, and model evaluation

20%

ML Implementation & Operations

SageMaker deployment, monitoring, security, cost optimization, and application services

How to Pass the AWS Machine Learning Specialty Exam

What You Need to Know

  • Passing score: 750/1000
  • Exam length: 65 questions
  • Time limit: 3 hours
  • Exam fee: $300

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

AWS Machine Learning Specialty Study Tips from Top Performers

1Focus on Domain 3 (Modeling, 36%) — it's the largest domain; master SageMaker training, hyperparameter tuning, and model evaluation metrics
2Know when to use different SageMaker deployment options: Real-Time Inference (low latency), Batch Transform (offline), Serverless Inference (sporadic), Asynchronous Inference (large payloads)
3Understand data engineering patterns: Kinesis Data Streams vs Firehose, Glue ETL vs EMR, S3 data lake architecture with Lake Formation
4Master model evaluation metrics: Accuracy, Precision, Recall, F1, AUC-ROC, RMSE, MAE — know when each is appropriate
5Know the ML services: Comprehend (NLP), Rekognition (vision), Polly (TTS), Transcribe (STT), Translate, Lex (chatbots), Personalize (recommendations), Forecast
6Understand feature engineering techniques: normalization, one-hot encoding, tokenization, handling missing values, and dimensionality reduction
7Practice with 200+ practice questions and aim for 80%+ on practice exams before scheduling
8Review the AWS ML Well-Architected Lens and SageMaker Best Practices whitepapers

Frequently Asked Questions

What is the AWS Machine Learning Specialty pass rate?

The AWS Machine Learning Specialty (MLS-C01) exam has an estimated pass rate of 55-65%. AWS requires a scaled score of 750 out of 1000. The exam is considered challenging and designed for experienced ML practitioners. Candidates with 2+ years of hands-on ML experience on AWS and thorough preparation typically pass on their first attempt.

How many questions are on the AWS Machine Learning Specialty exam?

The MLS-C01 exam has 65 total questions: 50 scored questions and 15 unscored pretest questions. You have 180 minutes (3 hours) to complete the exam. Questions are either multiple choice (one correct answer) or multiple response (two or more correct answers). Approximately 60% of questions are scenario-based, presenting real-world ML challenges on AWS.

What are the four domains of the MLS-C01 exam?

The four exam domains are: Domain 1 – Data Engineering (20%): S3, Kinesis, Glue, EMR, data ingestion and transformation; Domain 2 – Exploratory Data Analysis (24%): Data cleaning, feature engineering, visualization, and labeling; Domain 3 – Modeling (36%): Algorithm selection, XGBoost, deep learning, SageMaker training, hyperparameter tuning, and model evaluation; Domain 4 – ML Implementation & Operations (20%): Deployment, monitoring, security, and cost optimization.

How long should I study for the AWS Machine Learning Specialty exam?

Most candidates study for 8-12 weeks, investing 100-150 hours total. AWS recommends 2+ years of hands-on experience developing, architecting, or running ML workloads in AWS. Key study areas: 1) SageMaker ecosystem (training, tuning, deployment, monitoring). 2) Data engineering services (Kinesis, Glue, EMR). 3) Deep learning frameworks (TensorFlow, PyTorch). 4) Practice with 200+ questions and hands-on labs.

What AWS services are most important for the MLS-C01 exam?

Core services tested heavily: SageMaker (training jobs, hyperparameter tuning, model deployment, endpoints, monitoring); Data Engineering (Kinesis for streaming, Glue for ETL, EMR for Spark, S3 for storage); Analytics (Athena, Redshift); Application Services (Comprehend, Rekognition, Polly, Transcribe, Translate, Personalize, Forecast); Security (IAM, KMS, VPC endpoints). Deep knowledge of SageMaker is essential as it appears across all domains.

What is the difference between SageMaker Training Jobs and Processing Jobs?

SageMaker Training Jobs are used to train ML models on your dataset using built-in or custom algorithms. They handle infrastructure provisioning, distributed training, and model artifact output. SageMaker Processing Jobs are used for data preprocessing, feature engineering, and model evaluation. Processing Jobs are ideal for running feature transformation code on large datasets before training or running model evaluation after training.

When should I use built-in algorithms versus custom containers in SageMaker?

Use SageMaker built-in algorithms (XGBoost, Linear Learner, DeepAR, etc.) when they meet your requirements — they are optimized for performance and cost. Use custom containers (bring your own container) when you need specific libraries, frameworks, or custom code that built-in algorithms don't support. Custom containers provide flexibility but require more setup and management.