Next Ventures Data Engineer interview questions & guide 2026

The following questions are representative of the patterns observed in our recent hiring cycles. While the specific technical focus may shift based on the project requirements, these categories represent the core competencies we evaluate.

SQL and Database Proficiency

These questions test your ability to manipulate data and handle common data integrity challenges.

• How would you efficiently join multiple tables to extract specific insights?
• Describe your process for identifying and removing duplicate records in a large dataset.

Preparation at Next Ventures requires a blend of rigorous technical review and clear communication of your professional philosophy. You should focus on demonstrating both your "hard" engineering skills and your ability to operate within a team-oriented, high-stakes environment.

Technical Competence – We look for deep expertise in your core stack, particularly Python/Scala, SQL, and cloud platforms like Azure or AWS. You should be prepared to discuss not just how you use these tools, but why you chose them for specific architectural problems.

System Design & Architecture – You will be expected to articulate how you build for scale. Whether it is a Databricks implementation or a cloud-based ETL pipeline, be ready to explain the trade-offs between performance, cost, and maintainability.

Collaborative Mindset – We value engineers who view themselves as part of a larger business mission. You must demonstrate that you can translate technical complexity into clear, actionable updates for non-technical stakeholders and that you are comfortable working in agile, hybrid-remote settings.

The interview process at Next Ventures is designed to be thorough but professional, focusing on a balance between your technical problem-solving abilities and your behavioral fit. You can expect a series of discussions ranging from initial screens to deeper technical dives, often involving team members you would be working with directly. We aim for a process that respects your time while giving you a clear view of our engineering culture and the specific project challenges you will face.

This timeline illustrates the progression from initial screening through technical assessment to final behavioral interviews. Candidates should interpret these stages as an opportunity to build a narrative of their experience; use the earlier rounds to establish your technical credibility so you can focus on the "how" and "why" of your decision-making in the later, more strategic interviews.

Data Pipeline Engineering

We evaluate your ability to design robust, scalable systems that handle high volumes of data. We look for candidates who prioritize data quality and performance optimization.

Be ready to go over:

• ETL/ELT Design Patterns – Understanding the pros and cons of batch vs. streaming.
• Performance Tuning – Strategies for optimizing Spark jobs or SQL queries.

As a Data Engineer at Next Ventures, your work is foundational to our digital transformation projects. You will be responsible for designing and maintaining the data infrastructure that supports our clients' decision-making. This involves building scalable pipelines, ensuring data reliability, and working within a modern data stack that often includes Databricks, Spark, and cloud-native solutions.

You will act as a bridge between raw data and actionable insight, collaborating closely with data scientists and architects. You will not only be writing code but also contributing to architectural decisions and ensuring that our data platforms meet the highest standards of security, governance, and performance. You will be expected to operate with high autonomy, often delivering solutions in hybrid-work environments where clear communication is as important as technical execution.

A strong candidate for this position brings a combination of deep technical hands-on experience and the ability to thrive in a high-performing, professional environment.

• Must-have skills – 5+ years of data engineering experience, strong Python/Scala and SQL proficiency, proven experience with Cloud Platforms (Azure/AWS/GCP), and solid experience with ETL/ELT and data modeling.
• Nice-to-have skills – Experience in regulated industries like Banking, exposure to streaming technologies like Kafka, and a background in DevOps/CI/CD practices.
• Soft skills – Excellent stakeholder management, strong problem-solving mindset, and the ability to work independently in a senior, trusted capacity.

Q: How long does the hiring process typically take? While it can vary based on project urgency, most candidates complete the process within a few weeks. We aim to keep communication lines open and provide feedback as efficiently as possible.

Q: What is the most important trait for a successful candidate? Beyond technical proficiency, we look for "architectural maturity"—the ability to see the big picture and understand how your code impacts the long-term scalability and security of the client's business.

Q: Is there a lot of legacy work, or will I be using modern tools? Our projects are centered on modern data platforms, including Databricks and cloud-native architectures, ensuring you are working with the latest industry-standard technologies.

Q: What is the hybrid work expectation? Most of our roles in the Brussels region require 1–2 days on-site per week, with the remainder being remote. We value flexibility and prioritize finding the right balance for our teams.

• Prepare for the "Why" – Don't just explain how you used a tool; be prepared to explain why it was the best choice for that specific architecture.
• Master the Basics – Even for senior roles, we test core competencies like SQL and Linux operations; do not skip reviewing these fundamentals.
• Communicate your Process – When answering problem-solving questions, talk through your thought process aloud. We value how you structure a problem as much as the final answer.
• Be ready for behavioral scenarios – Use the STAR method (Situation, Task, Action, Result) to keep your answers concise and impactful.

The Data Engineer role at Next Ventures offers an exceptional opportunity to work on large-scale, high-impact projects that define the future of our clients' data strategy. By focusing your preparation on your technical stack, your ability to design scalable systems, and your readiness to collaborate in a professional environment, you will be well-positioned to succeed.

Remember that our interviewers are looking for a partner in engineering—someone who brings both technical excellence and a proactive, problem-solving mindset to the team. Take the time to reflect on your past projects, refine your architectural narratives, and stay confident in your expertise. You have the potential to make a significant impact here, and we look forward to seeing the unique perspective you bring to the table.

The salary data reflects the high-level, senior nature of our engagements, which are typically structured as long-term freelance or contract projects. These rates account for the specialized expertise and level of autonomy expected of a Senior Data Engineer operating in complex, regulated environments.