To succeed in your interviews, you need to understand exactly what our engineering team is looking for. Our evaluation is broken down into several core competencies that reflect the daily realities of a Data Engineer at Bestow.
Data Modeling and Architecture
Data modeling is the foundation of our analytics and underwriting systems. We evaluate your ability to design scalable schemas that balance read-and-write performance while maintaining strict data integrity. Strong performance in this area means you can confidently translate complex business requirements into logical and physical data models.
Be ready to go over:
- Dimensional Modeling – Understanding star schemas, snowflake schemas, and when to use fact versus dimension tables.
- Modern Data Stack – Experience with cloud data warehouses (like Snowflake or BigQuery) and transformation tools (like dbt).
- Data Governance – Designing systems that handle PII securely, which is critical in the insurtech space.
- Advanced concepts (less common) – Change Data Capture (CDC) patterns, slowly changing dimensions (SCDs), and data mesh architectures.
Example questions or scenarios:
- "Design a data model to track user progression through our online life insurance application funnel."
- "How would you handle late-arriving data in a daily batch pipeline?"
- "Explain how you would implement a Type 2 Slowly Changing Dimension for customer policy statuses."
Pipeline Engineering and Orchestration
Building resilient data pipelines is a core responsibility. Interviewers will test your ability to extract, transform, and load data from various sources into our central warehouse. We look for candidates who anticipate failures, build in robust logging, and understand orchestration mechanisms.
Be ready to go over:
- Batch vs. Streaming – Knowing when to use daily batch jobs versus real-time streaming for underwriting events.
- Orchestration – Designing DAGs (Directed Acyclic Graphs) using tools like Apache Airflow to manage dependencies.
- Idempotency – Ensuring pipelines can be rerun safely without creating duplicate records or corrupted states.
- Advanced concepts (less common) – Custom Airflow operators, optimizing Spark jobs, and handling API rate limits in ingestion frameworks.
Example questions or scenarios:
- "Walk me through how you would design an idempotent pipeline that ingests third-party medical data via a REST API."
- "Your Airflow DAG failed silently overnight. How do you troubleshoot and architect a solution to prevent this?"
- "Compare the trade-offs between an ETL and an ELT approach for our specific use case."
Python and SQL Proficiency
Your hands-on coding skills are evaluated through practical, real-world scenarios. We do not focus on obscure brainteasers; instead, we test your ability to manipulate data efficiently. A strong candidate writes clean, modular Python code and highly optimized SQL queries that scale across billions of rows.
Be ready to go over:
- Advanced SQL – Mastery of window functions, CTEs (Common Table Expressions), and query execution plans.
- Python Data Manipulation – Using Pandas, PySpark, or native Python data structures to clean and transform datasets.
- Performance Tuning – Identifying bottlenecks in slow-running queries and refactoring them for optimal performance.
- Advanced concepts (less common) – Writing custom UDFs (User Defined Functions) and handling complex JSON arrays in SQL.
Example questions or scenarios:
- "Write a SQL query using window functions to find the top three highest-converting user acquisition channels over a rolling 30-day period."
- "Given a messy JSON payload of user application data, write a Python script to flatten, clean, and validate the records."
- "How would you optimize a query that is performing a massive cross-join and timing out?"
Leadership and Behavioral
At the Senior Data Engineer and Staff Data Engineer levels, technical skills alone are not enough. We evaluate your ability to drive projects, influence stakeholders, and elevate the engineering culture. Strong candidates provide structured, metrics-driven examples of their past impact using frameworks like STAR (Situation, Task, Action, Result).
Be ready to go over:
- Technical Debt – Identifying, prioritizing, and resolving legacy infrastructure issues while continuing to deliver feature work.
- Cross-Functional Collaboration – Partnering with Data Science to deploy underwriting models and with Product to define tracking metrics.
- Mentorship – Guiding junior engineers through code reviews, pairing sessions, and architectural design documents.
- Advanced concepts (less common) – Driving organizational shifts toward new technologies or methodologies.
Example questions or scenarios:
- "Tell me about a time you had to push back on a product requirement because it compromised data integrity."
- "Describe a situation where you led a major migration or infrastructure overhaul. How did you manage the transition?"
- "How do you balance the need to deliver quickly with the need to build scalable, maintainable data pipelines?"