Lakehouse Fundamentals — ScreeningA phone-screen-style round on table formats. Answer from the mechanism — what the metadata layer actually does — not from vendor slogans.

What does a table format (Iceberg, Delta, Hudi) add on top of Parquet files in object storage?

Object storage guarantees that a single PUT is atomic. What does it NOT guarantee that a table needs?

A nightly job writes 900 new data files and crashes after 400. With a table format in charge, what does a reader see?

What is a snapshot?

Time travel (query the table as of last Tuesday) works because…

Why do streaming writers cause a 'small files' problem?

Compaction is…

Hidden partitioning (Iceberg) means…

Which statement about schema evolution in a table format is correct?

What role does the catalog play?