PMLE Practice Test 3 — 10 Questions

Question 1

A company deploys a classification model on Vertex AI for loan approval. After a month, they notice the precision has dropped significantly. What should they do first?

Accepted Answer

Check for data drift using Vertex AI Model Monitoring. A sudden drop in precision indicates that the model's predictions are no longer aligning with the ground truth, which is a classic symptom of data drift. Vertex AI Model Monitoring can automatically detect drift in feature distributions or prediction output compared to a baseline, allowing you to identify the root cause before taking corrective action. Retraining or reverting without first diagnosing the drift could waste resources or mask the underlying issue.

Answer

Retrain the model with more data

Answer

Increase the number of prediction nodes

Answer

Revert to the previous model version

Question 2

An ML team wants to use Vertex AI Hyperparameter Tuning to tune a custom training job. They have a budget of 50 trials and want to use an algorithm that balances exploration and exploitation. Which algorithm should they choose?

Accepted Answer

Bayesian optimization (Vizier default). Bayesian optimization (the default algorithm in Vertex AI Vizier) is the correct choice because it explicitly balances exploration and exploitation by building a probabilistic model of the objective function and using an acquisition function to select the next hyperparameter configuration. With a budget of 50 trials, this algorithm efficiently converges to optimal regions while still exploring uncertain areas, making it ideal for tuning custom training jobs where each trial is computationally expensive.

Answer

Random search

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Grid search

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Manual search

Question 3

A company wants to use Vertex AI Vector Search for real-time product recommendations based on user embeddings. They need to update the index frequently with new product embeddings without significant downtime. Which TWO options should they consider? (Choose 2)

Accepted Answer

Maintain two separate indexes: one for building and one for serving, and swap them after building.. Maintaining two separate indexes allows you to build a new index in the background while the existing index continues to serve queries. Once the new index is fully built and validated, you can swap it into production with minimal downtime. This is a common pattern for high-availability systems where index rebuilds are necessary.

Answer

Use batch updates to rebuild the entire index daily.

Answer

Increase the number of replicas on the deployed index.

Answer

Use a GPU-powered endpoint for faster indexing.

Question 4

Match each MLOps practice to its description.

Accepted Answer

CI/CD: Automates the processes of building, testing, and deploying ML models.. This matching question requires associating each MLOps practice (CI/CD, Model Monitoring, Data Versioning) with its correct description. The correct matches are: CI/CD automates building, testing, and deploying ML models (option A); Model Monitoring continuously observes model performance and detects data drift (option C); Data Versioning manages and tracks changes to datasets over time (option E). Common mistakes include confusing CI/CD with monitoring or versioning, or assigning model monitoring to data versioning tasks. The wrong options (B, D, F) are incorrect because they swap responsibilities: B wrongly attributes monitoring to CI/CD, D assigns versioning to monitoring, and F assigns CI/CD to versioning.

Answer

CI/CD: Continuously observes model performance and detects data drift.

Answer

Model Monitoring: Manages and tracks changes to datasets over time.

Answer

Data Versioning: Automates the processes of building, testing, and deploying ML models.

Question 5

A data scientist wants to deploy a trained TensorFlow model to Vertex AI for online predictions. They need to serve predictions with low latency and want to leverage GPU acceleration. Which machine type should they select when creating the Vertex AI endpoint?

Accepted Answer

n1-standard-4 with 1 NVIDIA Tesla T4. The n1-standard-4 machine type supports attaching GPUs such as the NVIDIA Tesla T4, which provides GPU acceleration for low-latency online predictions. Vertex AI endpoints require a machine type that allows GPU attachment, and the n1-series is one of the few families that supports GPUs, while the T4 offers a good balance of cost and performance for inference workloads.

Answer

n1-standard-4

Answer

e2-standard-4

Answer

n1-highmem-8

Question 6

You are fine-tuning a large language model (LLM) from Vertex AI Model Garden using a custom dataset. You need to minimize training cost while maintaining reasonable throughput. Which THREE strategies should you combine?

Accepted Answer

Use spot VM instances for training. Spot VM instances are significantly cheaper than on-demand instances, reducing training cost. They can be preempted, but for fine-tuning tasks that can checkpoint and resume, this trade-off is acceptable for cost savings.

Answer

Use full fine-tuning of all model parameters

Answer

Use TPU v4 pods for training

Question 7

You need to query a Vertex AI Vector Search index for nearest neighbours. The index is deployed on an endpoint. Which API method should you use to perform the query?

Accepted Answer

projects.locations.indexEndpoints.findNeighbors. The correct API method to query a deployed Vertex AI Vector Search index for nearest neighbors is `projects.locations.indexEndpoints.findNeighbors`. This method is specifically designed for vector similarity search against an index endpoint, returning the nearest neighbors for a given query vector. The other options either target the wrong resource (indexes instead of indexEndpoints) or use methods intended for different purposes like model prediction.

Answer

projects.locations.indexes.match

Answer

projects.locations.indexes.query

Answer

projects.locations.endpoints.predict

Question 8

You are using KFP SDK v2 to define a pipeline. You need to pass a large dataset between components. What is the best practice for passing data?

Accepted Answer

Write the data to Cloud Storage and pass the GCS URI as an artifact.. In KFP SDK v2, passing large datasets between components is best done by writing the data to Cloud Storage and passing the GCS URI as an artifact. This approach leverages KFP's built-in artifact tracking, ensures data persistence across container restarts, and avoids memory or disk limitations of ephemeral containers. The artifact is automatically serialized and passed as an input/output parameter, enabling efficient, scalable data exchange.

Answer

Use the component's temporary directory to share data between containers.

Answer

Pass the data as a serialized Python object in memory.

Answer

Store the data in a BigQuery table and pass the table reference.

Question 9

A data scientist wants to evaluate the performance of a BigQuery ML classification model on a test dataset. Which function should they use?

Accepted Answer

ML.EVALUATE. ML.EVALUATE is the correct function because it computes classification metrics (e.g., precision, recall, accuracy, F1 score, ROC AUC) directly on a trained BigQuery ML model using a provided test dataset or evaluation input. This is the dedicated function for assessing model performance after training, aligning with the task of evaluating a classification model on held-out test data.

Answer

ML.PREDICT

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ML.FEATURE_IMPORTANCE

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ML.TRAIN

Question 10

A financial company is building a fraud detection model. The dataset has 1% fraud cases and 99% legitimate transactions. Which technique should they use to handle the class imbalance?

Accepted Answer

Use class weighting or synthetic oversampling (SMOTE) during training. Class weights or resampling techniques like SMOTE are standard for imbalanced datasets. Option A is correct. Option B (undersampling majority) can lose information. Option C (collect more data) is impractical. Option D (no alterations) will bias the model.

Answer

Randomly undersample the majority class to balance the dataset

Answer

Collect more data until the fraud rate increases

Answer

Train without any modifications; the model will naturally handle it