Interview Questions

Explain Streams and Tasks in Snowflake.

Explain Time Travel in Snowflake.

Explain Triggers in SQL with examples and scenarios for use.

Explain a project where you had to influence stakeholders without having authority.

Describe a cross-team data project where you had to align architectural boundaries, ownership, and SLAs. How did you handle conflicting priorities, technical debt, and the scalability of communication as the number of stakeholders grew?

Walk through a production incident where data freshness or correctness was at risk. How did you balance immediate mitigation vs. root-cause remediation? What architectural changes would prevent recurrence, and what are the cost vs. reliability trade-offs?

Explain how to flatten a multi-level nested JSON file while loading it into BigQuery.

Explain normalization in databases and its importance. Write an SQL query to handle SCD-1 or SCD-3

Explain the differences between Redshift and Snowflake, and how I've used them in previous projects.

Explain the scalability, performance, and cost-efficiency of both Redshift and Snowflake in different use cases.

Explain the use of Elastic Resize vs. Classic Resize in Redshift.

Find non-common records in two tables (SQL EXCEPT or NOT IN)

Given a dataset, perform transformations: Filter rows where sales > 1000, Add a new column calculating a 10% discount on sales, Group data by region and calculate total revenue.

HAVING vs WHERE - explain

How do quarantine tables ensure data quality in downstream pipelines?

How do these policies affect query performance?

How do you convert 3 rows into one column in SQL?

How do you count occurrences in a column in SQL?

How do you create a new table with the same structure as an existing one?

How do you get new records from a table/file without a modified column? Discuss approaches like hashing or row comparison.