MACHINE LEARNING INTERVIEW QUESTIONS WITH ANSWERS

BASIC TO HIGH LEVEL QUESTIONS

->How to Prepare for a Machine Learning Interview?
->Machine Learning Interview Questions on Programming Skills
->Machine Learning Interview Questions on Algorithms and Theory
->Machine Learning Interview Questions on General Interest
->Sample Machine Learning Interview Questions for Practice

How to Prepare for a Machine Learning Interview?

If you are looking for how to prepare for Machine Learning interviews, you must grasp in-depth knowledge about the subject. Machine Learning Engineer interview questions are asked in the following four aspects:

Machine Learning – Probability, statistics, linear algebra, decision trees, and many more
Deep Learning – All about neural networks
Software – Algorithms and data structures
Domain Expertise – Vision, NLP, speech, compression, quantization, finance, hardware, computer architecture, and others

You should prepare from books at the initial stages. You must know the fundamentals of machine learning, its terminologies, and its scope to represent yourself as the right fit in your machine learning system design interview.

Machine Learning Interview Questions on Programming Skills:

Q1. How do you handle corrupted or missing data in a dataset?

You could find corrupted or missing data in a dataset by either dropping those rows or columns or replacing them with another value. There are two methods – isnull() and dropna(). These methods will help you find columns of missing/corrupted data. If you want to fill invalid values with a placeholder value, you could use the fillna() method.

Q2. Do you know what Spark is? Do you have any experience using it?

This is one of the commonly asked Machine Learning interview questions that test your knowledge and experience in Spark. A spark is a great tool used to handle massive datasets with speed. It is presently in demand. So, you must have sufficient knowledge and experience using it if you want to nail your machine learning interview.

Q3. What is the difference between a list and an array?

The differences between a list and an array are:

Lists and arrays are both data structures that store a collection of elements. However, there are some key differences between the two.

• Data types: Lists can store elements of any data type, while arrays can only store elements of the same data type.
• Size: Lists are dynamic, meaning that they can grow or shrink as needed. Arrays, on the other hand, have a fixed size.
• Performance: Arrays are generally faster than lists for operations that require accessing elements by index, such as searching and sorting. This is because arrays store elements in contiguous memory locations, while lists store elements in a linked list.
• Flexibility: Lists are more flexible than arrays, as they can be easily modified. Arrays, on the other hand, are less flexible, as they cannot be easily modified without causing the elements to be re-allocated.

In general, arrays are a good choice for storing large amounts of data of the same data type, and lists are a good choice for storing smaller amounts of data of different data types.

Here is a table that summarizes the key differences between lists and arrays:

Q4. What is a hash table?
A hash table is a data structure that produces an associative array. A hash table is used for database indexing. In a hash table, a key is mapped to certain values through a hash function.

Q5. How are foreign and primary keys related to SQL?
If you are attempting Machine Learning interview questions at top-ranked technical or FAANG companies, you must have a profound knowledge of various data formats. SQL is one of those. You should be familiar with how to manipulate SQL databases. The key differences between a primary and foreign key are:

Q6. What are data types supported by JSON?
You must be adept in JSON to answer these types of Machine Learning interview questions. You can manipulate six data types in JSON – numbers, strings, objects, null values, arrays, and booleans.

Machine Learning Interview Questions on Algorithms and Theory

Q1. What is the difference between bias and variance?
Bias is an error that occurs due to overly simplistic assumptions or erroneous assumptions in the learning algorithm. If you use bias, it can lead to the model underfitting your data with low predictive accuracy.

On the other hand, variance is an error due to complexity in the learning algorithm. In variance, your data gets highly sensitive to high degrees of variation, leading your model to overfit the data. You’ll end up carrying noise from your training data for your model to be useful for your test data.

Q2. How will you differentiate between supervised and unsupervised machine learning?

Supervised learning required training labeled data. For instance, to classify a supervised learning task, you must first label the data you’ll use to train the model. Contrastingly, unsupervised learning does not require labeling data explicitly.

Q3. How does a ROC curve work?

ROC is a graphical representation of the contrast between true positive rates and the false positive rate at various thresholds. You should know that it’s often used as a proxy for the trade-off between the true positives (sensitivity of the model) vs. the false positives (fall-out or probability to trigger a false alarm).

Q4. What is Bayes’ theorem? How is it useful in machine learning?

To answer Machine Learning interview questions based on Bayes’ theorem, you must have clear concepts on such mathematical topics. Using Bayes’ theorem, you can get the posterior probability of an event given that is known as prior knowledge. Bayes’ theorem notably includes the Naive Bayes classifier.

Q5. What is ‘Naive’ Bayes naive?

Naive Bayes is considered naive because it makes assumptions impossible to see in real-life data. Despite its practical applications, especially in text mining, the resulting probability implies the absolute independence of features, which is a condition that can never be met in real life.

Q6. What is the difference between L1 and L2 regularization?

L1 is binary/sparse, with many variables assigned a 1 or 0 in weighting. It corresponds to setting a Laplacean before the terms. In contrast, L2 regularization tends to spread error among all the terms. L2 corresponds to a Gaussian prior.

Machine Learning Interview Questions on General Interest

Q1. Do you have research experience in machine learning?

You must know that various top technical and FAANG companies look for experienced machine learning engineers. So, while answering these types of Machine Learning interview questions, you must highlight your experiences to make a difference in your hiring process. You can tell them about the research papers co-authored or supervised by leaders in the field.

Q2. What are your favorite use cases of machine learning models?

These types of questions are asked to test your deep knowledge about machine learning in an interview. Make sure to have a few examples in mind and describe what resonated with you. You must demonstrate an interest in how machine learning is implemented.

Q3. Where do you usually source datasets?

These are the most asked Machine Learning interview questions. You should be passionate about machine learning to answer such questions. Answering these questions will strongly impact the interviewer at any FAANG or top technology company. You must have adequate knowledge about datasets and which one is great.

Q4. What are your favorite APIs to explore?

You need to have clear concepts on APIs to answer these types of Machine Learning interview questions. If you have worked with external data sources, it will be easier to answer these questions. You can mention the kinds of experiments and pipelines you have run in the past. You can also mention how APIs’ usage has transformed over the past years.

Q5. How do you think quantum computing will affect machine learning?

These types of Machine Learning interview questions test your interest in quantum computing. You must answer these questions concerning the present-day scenarios and how this new format and way of thinking will change the future. You must demonstrate your knowledge in this area to show your keen interest in machine learning at a higher level.

Click Here to Sample Machine Learning Interview Questions for Practice