Toptal Data Scientist Interview Questions
& Process
Real candidates share what happened, how many rounds they had,
and how the experience turned out.
Based on 20 interview experiences · FREE TO READ
Candidate interview experiences
First-hand accounts from people who interviewed at Toptal.
Toptal
Data Scientist
Entry Average Positive experience No offer 5 rounds
Interview process
Recruiter call Technical screen Onsite Take home Background check
Interview formats
Coding Behavioral Technical
Toptal's interview process for software engineers is in a few stages: First, there's a Language and Personality Screening where candidates take a test to see how they communicate, solve problems, and if they fit the culture. Then, a Technical Screening where candidates do a timed coding challenge relevant to their skills. After that, a Live Interview with a Toptal engineer to chat about your background, tech skills, and how you approach problems. Next, you'll get a paid Test Project to show off what you can do. Finally, a Final Review looks at your whole performance to see if you meet Toptal's high standards. The whole process is meant to find top software engineering talent so clients get great work from experienced people.
Confirmed questions1 question
- Can you merge overlapping intervals from a given array `intervals` where each interval is `[start_i, end_i]`, and return the result sorted?
Toptal
Data Scientist
Entry Average Negative experience No offer 2 rounds
Interview process
Technical screen Presentation Technical screen
Interview formats
Coding Presentation Technical
First, there was a 90-minute Codility test. Then, a remote interview with screen sharing, which included a presentation of my background and a coding test. The process was neat and the interviewer was polite, but the content focused heavily on "coding fast." The technical interview's main criterion was coding speed (20 minutes) to solve problems with low conceptual difficulty. It didn't matter if you were on the right track, thinking correctly, using the right tools, considering future implications, or proposing alternative solutions; if you didn't get the result, you didn't pass. This approach might suit a junior software developer, but it's not ideal for a data scientist, where reasoning is key, not just coding speed. This type of test seems to attract junior profiles, which is typical for Toptal. Others should probably avoid it.
Confirmed questions1 question
- Can you code this in 20 minutes?
Toptal
Data Scientist
Mid Average Negative experience No offer 3 rounds
Interview process
Technical screen Technical screen Presentation
Interview formats
Coding Coding Technical
It was Codility, then live coding then a project. Codility was easy. Live coding wasn't difficult but the interviewer was extremely biased. For example, I always check if code is working as is, and only then handle the missing variables. And the interviewer was like : why didn't you check missing variables and was overall an evil person about it. Also I was asked about the accelerometer data. And I asked what does accelerometer mean (because I am not good at physics) and he was angry that i asked and was like: "just ignore it and answer the question", as if like saying that subject matter expertise is not important, it is just important to analyze data like a robot.
Confirmed questions3 questions
- Given data perform a simple classification.
- What does accelerometer data mean?
- Analyze the accelerometer data.
Toptal Data Scientist Interview Questions
Quoted word for word from Toptal interview reports.
“Write a function for mutual information using numpy.”
Read reports →“Given data perform a simple classification.”
Read reports →“What is a confusion matrix?”
Read reports →“Can you merge overlapping intervals from a given array `intervals` where each interval is `[start_i, end_i]`, and return the result sorted?”
Read reports →“What does accelerometer data mean?”
Read report →“Could you explain what regularisation is?”
Read report →“Do you have a preferred domain?”
Read report →“Can you tell me about neural networks?”
Read report →“What kind of industry are you looking for?”
Read report →Formats, difficulty and experience
Across all 20 Toptal interview reports.