10 Machine Learning Engineer interview questions and answers

Find and hire talent with confidence. Prepare for your next interview. The right questions can be the difference between a good and great work relationship.

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Please discuss why tradeoff between bias and variance exists in the training dataset.

Asking a question about machine learning algorithms will provide you with important information on how the candidate understands machine learning theory. You could potentially ask many different versions of this question, substituting the bias-variance tradeoff for another algorithm topic:

  • Bayes’ Theorem and the Naïve Bayes classifier
  • Type I and Type II errors
  • High variance and high bias issues in training data and test sets
  • Deep learning
  • Decision tree pruning
  • Cross-validation techniques
  • Ensemble techniques like bagging and boosting
  • KNN classification algorithm and k-means clustering
  • Deep learning and neural networks
  • Linear regression and logistic regression
  • How to avoid model overfit
  • K-folds cross-validation techniques
  • Logistical regression model evaluation techniques
  • Ensemble learning techniques
  • L1 and L2 regularization, and false positives and false negatives
  • Supervised learning and unsupervised learning, and labeled and unlabeled data
  • How to avoid model overfitting
  • Handling corrupted data in Pandas
  • Dimensionality reduction
  • Precision and recall/true positive rates
  • The Confusion Matrix and classification problems
  • Data binarizing and feature engineering
  • How to deal with missing values in a dataset
  • Support Vector Machines (SVM)
  • ROC curves
  • Ensemble methods
  • Model accuracy and model performance
  • Principal Component Analysis (PCA)
  • Evaluating machine learning model effectiveness with the confusion matrix and F1 score
  • Algorithms like Random Forest, Clustering Algorithm, and Gradient Boosting Algorithm
  • False negative, true negative, false positive, and true positive

How would you describe a hash table and what it’s used for?

Machine learning interview questions like this one help you to understand how well a freelancer understands and can apply machine learning principles. In addition to this question, you might ask about other types of machine learning model topics:

  • Data pipelines
  • Common data visualization tools like Python, Tableau, and Plot.ly
  • SQL primary and foreign keys
  • Parallel implementation codes
  • Corrupted data best practices

What types of machine learning are you most familiar with?

Ask a candidate whether they’re more comfortable and experienced with supervised, unsupervised, or reinforcement learning. Of course, experience with all types of learning is ideal, but it’s important to make sure that a machine learning engineer is well-versed in the type of machine learning your business uses most often.

What qualities do you feel make you a great machine learning engineer?

Giving candidates a chance to highlight their relevant skills and experiences can help you to understand their strengths better. Look for qualities that align with the position you’re advertising, like experience with the coding and programming languages you use, previous teamwork and problem-solving experience, and excellent analytical skills.

What changes would you make to our existing data processes?

This question can show you whether a candidate is paying attention, how well they monitor details, and how they might make a difference at your business. A candidate can demonstrate creative thinking and their ability to come up with ideas to improve your operations.

What are some of your biggest accomplishments in machine learning?

Asking about a freelancer's previous projects can highlight some of their strengths and the potential they could bring to your business. Be sure to ask for details on the contractor's role, the steps they took to ensure the project was a success, and why they’re proud of the accomplishment.

What challenges have you previously faced with machine learning projects, and how did you overcome them?

How a candidate handles and finds solutions to challenges can demonstrate that they’re ready for their challenges while on the job. This question can also provide insight into how a candidate views challenges and their overall attitude toward work.

What machine learning models have you previously used, and which do you find most helpful?

An interviewee's response to this question gives you an idea of their experience and versatility. It can also highlight their awareness of machine learning implementations and the end effects of their work.

What is your ideal work environment?

Ask how a freelancer works best and what type of work culture they’re most comfortable within. Think about whether the environment they’re describing aligns well with your business, and whether they might be a good fit for your work culture.

Do you have experience working remotely?

If a candidate is working remotely, then ask if they’ve performed remote work before. Be sure to discuss any challenges that they experienced while working remotely and any concerns they might have around the arrangement.



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Machine Learning Engineers you can meet on Upwork

  • $120 hourly
    Austin F.
    Machine Learning Engineer
    • 5.0
    • (7 jobs)
    Brandon, MS
    vsuc_fltilesrefresh_TrophyIcon Machine Learning
    Amazon Web Services
    QA Automation
    Data Visualization
    Unit Testing
    Data Analytics
    ML Automation
    Data Science
    I am a software developer and data professional with over five years experience. My business philosophy is to provide solutions that generate value for the client long after I deliver them. I'm currently undergoing rigorous study to better understand and integrate various technologies to offer more comprehensive support to my clients. I can help implement: - various types of automation, including quality assurance automation - certain cloud solutions with GCP, AWS, and Microsoft AzureML - data transformations - machine learning models - dashboards - command-line interfaces - financial analyses - Jupyter notebooks - spreadsheet solutions (Google Sheets and Excel) - various types of interactive visualizations - software modules (in particular, I'm currently learning to build Python modules in Rust for faster performance) I have formal training as an engineer up to the Master's level. I have training from past full-time roles as research engineer and data analyst. I attribute much of my current skills to ongoing self-study using online resources such as Packt and O'Reilly technology and business training. I am also developing my skills in Rust and online cloud services. As a research engineer, I developed experimental machine learning models with Python and wrote corresponding technical reports. These efforts were also the subject of my graduate work. As a data analyst, I collected and analyzed data from solar energy infrastructure projects and conducted external market research to determine future project viability in different regions. Since joining Upwork, I have assisted clients with ML and data engineering tasks. As mentioned earlier, I am currently training to be a full-stack solutions architect with both coding and strategic planning offerings.
  • $35 hourly
    Karthick N.
    Machine Learning Engineer
    • 4.9
    • (18 jobs)
    Namakkal, TN
    vsuc_fltilesrefresh_TrophyIcon Machine Learning
    Website Content
    Internet of Things Solutions Design
    Ruby on Rails
    Artificial Intelligence
    Computer Vision
    Deep Learning
    I've studied computer science. I have an experience of Web Development with the flavor of HTML, CSS, Bootstrap, JavaScript and other web development tools. I really enjoy the fact that thousands of users use applications that are developed by me. The ultimate dream is that one day thousands will grow into millions or billions. I HAVE A DREAM! Overall if summarized my experience that would be exploring, organizing information, problem-solving, and implementation. Languages are essential for expressing your programming skills overall. From the EXPLORING attribute, I have worked around lots of different languages. 1) Ruby 2) AngularJS 3) Javascript 4) Vuejs 5) Python ( a new sensation I always wanted to explore Erlang but then I found this beauty. Python leverages the Erlang VM, known for running low-latency, distributed and fault-tolerant systems, while also being successfully used in web development and the embedded software domain.) In assistance to above languages below frameworks come into play, 1) Ruby on Rails 2) Django Databases are the main central storage of any web application. I got experience in both SQL and NoSQL 1) Postgres 2) MongoDB 3) SQLite 4) Mysql The game never ended on the server-side for me. The frontend/public-facing part of the web application has been also highly evolved. Everyone wants to use Single Page Applications - The SPAs. I got experience in the following 1) Angular JS 2) React JS Testing and Test Driven Development(TDD) is also an essential thing for any solid application. I can write automated tests in following 1) Rspec 2) Capybara Deployment is essential to distribute your application out in the wild. I got experience in the following tools and technologies 1) AWS 2) Google Cloud Platforms 3) Capistrano 4) Mina 5) Nginx 6) Passenger Phusion 7) Puma 7) Unicorn
  • $45 hourly
    Adnan K.
    Machine Learning Engineer
    • 4.9
    • (77 jobs)
    Chennai, TN
    vsuc_fltilesrefresh_TrophyIcon Machine Learning
    Data Analytics
    Microsoft PowerApps
    Data Analysis
    Statistical Analysis
    Exploratory Data Analysis
    Financial Analysis
    Data Modeling
    Power Query
    Microsoft Excel
    Microsoft Power BI
    ⭐⭐⭐⭐⭐ "Adnan is an incredibly determined programmer, with a curiosity that makes him so fun to work with. He gives great insight and creates models that are accurate and effective." As a top-rated freelancer on UpWork, I have successfully completed over 60 projects, receiving numerous five-star reviews and overwhelmingly positive feedback from satisfied clients. I am a data analytics and visualization expert, where I have assisted clients across multiple industries in generating actionable insights from their data. My clientele includes reputed organizations from diverse fields including: ✅ Genesee & Wyoming Inc (A railroad logistics company based out of North America and Europe) ✅ Chegg Inc (An EdTech company based out of the USA) ✅ Kuelap Inc (A funding solution provider for banks and fintech companies based out of Indonesia) ✅ Nakamichi (A consumer electronics manufacturing company based out of China) ✅ TestGorilla (An employee pre-screening platform based out of the Netherlands) With a solid background in Data Analysis spanning over 12 years, I possess a wealth of experience in both the business and technical realms. This affords me a distinct advantage in understanding problems from a business standpoint and delivering technical solutions that precisely align with clients' needs. To get a glimpse of my expertise, please refer to my portfolio section where you can view some of my successfully completed projects. ⭐ Here's what I can bring to your project ⭐ ✅ Extensive expertise in working with a diverse range of Data Visualization tools, including Power BI, Tableau, Looker Studio ✅ Significant experience in handling large enterprise data and intricate data models ✅ Extensive experience constructing intricate Machine Learning algorithms, automating workflows, and performing advanced data wrangling and statistical analysis using Python. ✅ Extensive experience building Power Apps to help organization streamline operations ✅ Ability to rapidly identify and diagnose reporting and dashboarding errors, as well as to pinpoint potential issues ✅ Expert-level proficiency in designing ETL (Extract, Transform, Load) processes using Power Query and Python ✅ 24/7 ultra-reliable communication, I ensure that clients are always kept informed of the project status ✅Committed to assisting you in achieving success and delivering significant value to your business ⭐ Why you should choose me over other freelancers ⭐ ✅ I prioritize providing exceptional value to each of my clients and earning their trust, as evidenced by their positive reviews. I continuously strive to exceed expectations. ✅ Exceeding expectations and over-delivering is a fundamental aspect of my work. I am delighted when clients are left with a sense of amazement, and my goal is to consistently deliver work that leaves them saying "WOW". ✅I am highly responsive and committed to maintaining open lines of communication with my clients. ✅ My resilience is a defining attribute that is evident in my approach to client work. Clients, both past and present, can attest to my unwavering commitment to finding solutions to any issue that may arise. ✅ Kindness is an integral part of who I am, and it extends to every aspect of my life. I firmly believe in treating everyone with respect and empathy, and I am committed to improving my clients' situations. 🏆 Reviews and feedback from high-profile clients 🏆 The client reviews below describe the quality of work and value that you can expect from working with me. "Adnan was extremely professional and a joy to work with. He listened attentively to our business needs and work diligently to produce content that was outstanding for both me and my customers. I am really thrilled with my experience working with him and would strongly endorse him to anyone looking for a talented data visualization specialist and dashboard designer." – Will Schober, Kuelap Inc "Adnan is an expert in data visualization. He communicated with me about each and every step of the project. He really exceeded my expectations by delivering 3 excellent deliverables and highly valuable recommendations. Besides, he is polite, professional and friendly. I highly recommend Adnan and will definitely work with him again. Thank you!" – Zainab, Einitas "Awesome Job! 5 Stars service. Adnan is great, he communicated with me on every stage of the process which was really important. We did zoom calls and messaging via the upwork platform. Communication was important to me and Adnan met my expectation, and he delivered an outstanding project for me. Exactly what I wanted! Not only that, I made additional request for coding and Adnan did it for me within the project time frame. I will definitely go back to Adnan for addition future project! I am happy working with him." – Brian Law, Nakamichi "Everything was great - quality of work - meet the deadline - he is smart and clearly understood the requirement" - Pete Clarke, Diversa Health
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