Toptal Data Engineer Interview Questions + Guide in 2025

Toptal is a leading talent marketplace that connects clients with top freelancers across various fields, including software development, design, and finance.

As a Data Engineer at Toptal, you will play a pivotal role in building and maintaining the data infrastructure that supports analytics and business intelligence efforts. Key responsibilities include designing and implementing data pipelines, optimizing data flow and collection processes, and ensuring data integrity and accessibility for stakeholders. Required skills encompass proficiency in programming languages such as Python or Java, experience with big data tools like Hadoop or Spark, and familiarity with relational and non-relational databases. Ideal candidates should exhibit strong analytical and problem-solving abilities, an effective communication style, and a passion for leveraging data to drive business decisions. Toptal values collaboration and innovation, so a proactive mindset and the ability to work well in a remote team environment are essential.

This guide will equip you with insights into the expectations and nuances of the interview process at Toptal, allowing you to prepare effectively and confidently showcase your abilities.

The interview process for a Data Engineer position at Toptal is structured and consists of multiple stages designed to assess both technical skills and cultural fit.

1. Initial Screening

The process begins with an initial screening call, typically conducted by a recruiter. This conversation focuses on understanding your background, career journey, and motivations for applying to Toptal. The recruiter will also assess your English proficiency, as effective communication is crucial in a remote work environment.

2. Online Coding Assessment

Following the initial screening, candidates are required to complete an online coding assessment. This assessment usually consists of multiple coding challenges that test your problem-solving abilities and technical knowledge. You will have a set time limit, often around 120 minutes, to complete these tasks, which may range from easy to medium difficulty levels. It is advisable to practice coding problems on platforms like HackerRank or LeetCode to prepare effectively.

3. Live Coding Interview

If you perform well in the online assessment, the next step is a live coding interview. This session typically lasts about 30 to 60 minutes and involves solving coding problems in real-time while sharing your screen. You may be asked to explain your thought process as you work through the problems, so be prepared to articulate your reasoning and approach clearly.

4. Take-Home Project

Candidates who successfully navigate the live coding interview will be assigned a take-home project. This project is designed to evaluate your practical skills and may require a significant time investment, often estimated at around 20 hours. You will be expected to deliver a fully functional solution, and the project will be reviewed in a follow-up call with a technical team member.

5. Final Review

The final stage of the interview process involves a review of your performance across all previous stages. This may include discussions about your take-home project, as well as any additional technical or behavioral questions. The goal is to ensure that you meet Toptal's high standards for talent and are a good fit for their team.

As you prepare for your interview, it's essential to familiarize yourself with the types of questions that may be asked during each stage of the process.

Practice for the Toptal Data Engineer interview with these recently asked interview questions.