Afiniti Data Engineer interview questions & guide 2026

The questions below represent the patterns observed in Afiniti interview cycles. While the specific technical tasks may vary by team, the core focus remains on your ability to handle data with precision and efficiency.

SQL and Database Fundamentals

This category tests your core competency in data manipulation, database design, and your ability to write performant queries under pressure.

• Order of SQL query execution.
• Difference between primary key and unique key.

Preparation for Afiniti requires a balance of deep technical recall and the ability to think through complex logic puzzles. Approach your study by focusing on the "why" behind your code, not just the syntax.

Technical Proficiency – You must be fluent in SQL and Python. Interviewers expect you to write error-free, optimized code on the spot, so practice writing queries without IDE assistance.

Architectural Thinking – Beyond writing queries, demonstrate an understanding of data warehousing and system scalability. Be prepared to explain how your design choices impact long-term data integrity and system performance.

Analytical Rigor – Afiniti values candidates who can solve complex, non-standard logic problems. Practice your ability to articulate your thought process clearly, even if you are still working toward the final answer.

The interview process at Afiniti is designed to be efficient and highly focused on technical output. Most candidates encounter a structured progression that begins with a screening, followed by technical assessments—which may include online tests for SQL, math, and IQ—and concludes with multiple rounds of interviews. These interviews are typically led by senior engineers and department leadership, ensuring that both your technical skills and your ability to fit into the team’s high-performance culture are thoroughly vetted.

This visual timeline highlights the progression from initial screening to final leadership interviews. Use this to pace your preparation, ensuring you have refreshed your core technical skills before the first technical screen and saved your "big picture" architectural thoughts for the final interview rounds.

SQL and Database Mastery

This is the most critical evaluation area. You will be tested on your ability to write complex queries and your knowledge of database internals.

Be ready to go over:

• Joins and Set Operations – Mastery of INNER, OUTER, and CROSS joins is expected.
• Advanced Querying – Using window functions, ranking, and complex aggregations (e.g., finding the Nth maximum salary).
• Optimization – Discussing indexing strategies, execution plans, and reducing query complexity.

Example scenarios:

• Writing a query to find the Nth lowest or highest salary in an employee table.
• Identifying which join type is appropriate for specific data merging requirements.

Data Engineering Infrastructure

Understanding how data moves and evolves is vital for this role.

Be ready to go over:

• SCD Management – Explaining how to handle changing data over time using SCD types.
• Data Warehousing – Concepts like surrogate keys, fact tables, and dimension tables.
• Workflow Orchestration – Basic familiarity with tools like Airflow or similar ETL scheduling platforms.

As a Data Engineer, you are responsible for the end-to-end lifecycle of data within Afiniti. Your day-to-day will involve building and maintaining scalable ETL pipelines, optimizing database schemas for high-concurrency environments, and collaborating with data scientists to ensure they have the clean, reliable data needed for model training.

You will often find yourself troubleshooting data quality issues, automating manual data tasks, and contributing to the design of the data warehouse. Because Afiniti operates on a global scale, you must be comfortable with the operational demands of deployments and the need for high-availability systems. You will work closely with other engineers and product teams to translate business requirements into efficient, performant data structures.

A strong candidate for this role possesses a blend of deep technical expertise and the mental agility to handle abstract problem-solving.

• Must-have skills: Advanced SQL, Python programming, understanding of Data Warehousing concepts (SCDs, Star/Snowflake schemas), and performance optimization techniques.
• Nice-to-have skills: Experience with Airflow, cloud-based data platforms, or time-series data modeling.
• Soft skills: Clear communication, the ability to explain complex technical concepts to non-technical stakeholders, and a high degree of comfort with working in a fast-paced, high-pressure environment.

Q: How difficult are the interviews? A: Candidates generally report the difficulty as average to high. The technical bar is consistent, focusing heavily on your ability to write performant SQL and solve logic-based puzzles.

Q: What is the best way to prepare for the logic/math questions? A: These are designed to test your raw problem-solving speed. Practice common brain teasers and focus on explaining your logic out loud—interviewers at Afiniti want to see how you approach an unknown problem.

Q: How long does the process take? A: The process is notably fast, with some candidates moving from initial application to final interview within two weeks. Ensure you are ready to engage immediately once you apply.

Q: Is there a coding test? A: Yes, expect to be asked to write SQL and Python code during your technical sessions. Some rounds are strictly hands-on, requiring you to solve problems in real-time.

• Think Out Loud: When solving a logic puzzle or writing a complex SQL query, explain your steps. The interviewers are evaluating your thought process as much as the final answer.
• Master the Basics: Do not overlook fundamental SQL concepts like the order of operations or the differences between various join types. These are frequent points of failure.
• Be Ready for Speed: Because the process is fast, prioritize your preparation immediately after applying.
• Showcase Your Impact: When discussing past projects, emphasize the technical challenges you solved and the specific outcomes of your work.

The Data Engineer role at Afiniti is a high-impact position that demands both technical depth and sharp analytical reasoning. By focusing your preparation on SQL performance, database architecture, and systematic logical problem-solving, you will be well-positioned to navigate the interview process successfully. Remember that your ability to communicate your thought process is just as important as the code you write.

You can explore additional interview insights, practice questions, and preparation resources on Dataford. Dedicate time to these materials to sharpen your skills, and approach your interviews with the confidence that you have prepared for the specific challenges this role presents.

The compensation data provided reflects the market range for this position, typically encompassing base salary and potential performance-based components. This range varies depending on your years of experience, the specific team you are joining, and your geographic location. Use this information as a benchmark for your own expectations while focusing primarily on demonstrating your value during the technical evaluation.