Databricks Senior Software Engineer Interview Questions

1.Tell me about a time you chose to use an open-source library or contribute back to open source instead of building something from scratch. What problem were you solving and how did you make that decision?

2.Tell me about a time you identified a process or tool that was slowing down multiple teams and took it upon yourself to improve it. What was your approach and what happened?

3.Describe a time when you saw something broken or inefficient outside your immediate responsibilities and decided to fix it anyway. What was the situation and what did you do?

4.Tell me about a time when being direct or transparent about a difficult situation helped you achieve a better outcome than if you had sugar-coated it.

5.Walk me through a project where you were under significant time pressure but couldn't compromise on quality. How did you balance speed and quality, and what tradeoffs did you make?

6.Describe your experience contributing to an open-source project where your changes had to meet the community's standards, not just your company's needs. What was challenging about that process?

7.Write a function that efficiently finds all tables in a Databricks workspace that haven't been accessed in the last 90 days. Assume you have access to audit logs via an API.

8.Design a caching layer for MLflow model serving that can handle both real-time inference requests and batch prediction jobs. What are your main considerations?

9.A customer is running Spark jobs on our platform and complaining about inconsistent query performance - the same query sometimes takes 2 minutes, sometimes 20 minutes. Walk me through how you'd debug this.

10.You need to implement rate limiting for Databricks REST APIs that handle both interactive notebook requests and programmatic ETL jobs. How would you design this to be fair but not hurt user experience?

11.You're working on Delta Lake and notice that concurrent writers are occasionally creating conflicts that require expensive merge operations. How would you redesign the conflict resolution to minimize these expensive merges while maintaining ACID guarantees?

12.Design an API for Unity Catalog that allows customers to query data lineage across multiple workspaces. What are the key challenges and how would you handle them?

13.Design a configuration management system that can push updates to 10,000+ Databricks clusters across different cloud providers without causing downtime. What are your key design considerations?

14.You're building a data discovery service that helps users find relevant datasets across a Databricks lakehouse with millions of tables. How would you design the search and recommendation engine?

15.You need to build a job scheduler for Databricks that can handle 100,000+ concurrent Spark jobs across multiple cloud regions. Walk me through your design approach.

16.How would you design a distributed logging system that captures all SQL queries across Databricks workspaces for Unity Catalog's audit trail? Consider both compliance and performance requirements.

17.Design a metadata service for Delta Lake that tracks schema evolution across billions of tables while supporting both ACID transactions and concurrent reads. How would you handle the scale and consistency requirements?

18.Design a real-time feature store for Mosaic AI that needs to serve 50 million feature lookups per second with sub-10ms latency. How do you handle both batch and streaming feature updates?

19.Tell me about a time you had to convince engineering leadership to adopt or change a technical approach, even though you weren't the most senior person in the room. How did you build your case?

20.Describe a situation where you saw a customer struggling with our platform or data pipeline, and you went beyond your normal responsibilities to solve their problem. What did you do?

21.Tell me about a time you had to lead a cross-functional project where different teams had conflicting priorities or technical approaches. How did you navigate those conflicts?

22.Walk me through a time when you mentored someone more junior and they initially pushed back on your technical guidance. How did you handle that situation?

23.Describe a time when you had to make a significant architectural decision that would impact multiple teams, but you had incomplete information and a tight deadline. How did you approach the decision-making process?

24.Tell me about a time when you championed an open-source approach or contribution that faced internal resistance because it seemed to conflict with business priorities. How did you make the case?

25.Our Unity Catalog team reports that 40% of data governance requests are for table access permissions that should be automated. Estimate how much engineering time we're losing annually, and walk me through how you'd prioritize fixing this.

26.Estimate the revenue impact if we reduced MLflow model deployment time from 10 minutes to 30 seconds for all customers. Walk me through your calculation and key assumptions.

27.A Fortune 500 customer says their Spark jobs on our platform are 30% slower than their on-premise cluster, but they're using the same code. Walk me through how you'd analyze this performance gap.

28.Estimate how much compute cost Databricks saves customers annually by using Photon Engine versus standard Spark. What assumptions drive your calculation?

29.Our telemetry shows that 60% of Delta Lake tables created by customers never get queried after the first week. How would you investigate whether this indicates a problem with our platform or normal user behavior?

30.A major customer wants to migrate 50TB of historical data from their traditional data warehouse to Delta Lake, but they need zero downtime and want to validate data integrity throughout. Walk me through your migration strategy.