Payments / marketplace
Stripe interview themes
What people report studying for — not a take-home dump. Last editorial update 2026-08-01.
Rounds you should expect
SQL screen
Dedup to latest customer, anti-joins that survive NULL, and a revenue query that does not fan out on a payments table.
Pipeline design
Exactly-once vs at-least-once into a warehouse. They want the sink story, not Kafka slogans.
Debugging
A dashboard doubled overnight. Walk the grain from gold to source in five minutes.
Recently added questions
2026-09-10 · Ledger events vs balances
Gold is a running-balance column you UPDATE. A webhook retries. What shipped?
Two mutations, one economic event. Model immutable ledger entries and sum them. Idempotency on (payment_id, event_id), not an overwrite.
From the question bank
hard · SQL · SQL
Deduplicate to the latest customer row. Why not filter the window in WHERE?
Practice →easy · SQL · SQL
EXISTS vs IN for an anti-join. Which do you write first?
Practice →medium · SQL · SQL
You need “customers who ordered in January and never in February.” Write the shape, not the dialect.
Practice →medium · SQL · SQL
LAG(amount, 1) IGNORE NULLS vs the default. Give a revenue example.
Practice →medium · Warehouse · Snowflake
Streams and Tasks vs an external orchestrator. How do you choose?
Practice →medium · Warehouse · Snowflake
Zero-copy clone of prod for a destructive test. What do you warn finance?
Practice →easy · Warehouse · Snowflake
DIRECTORY tables and a stage full of JSON. Why is SELECT $1:id from the stage a bad gold pattern?
Practice →medium · Data modeling · dbt
ref() vs source() — why does the distinction matter in an incident?
Practice →hard · Data modeling · dbt
Two marts both named fct_revenue. How did that happen, and how do you kill one?
Practice →medium · Orchestration · Airflow
deferrable sensors vs poking every 30s. What did you free?
Practice →easy · Orchestration · Airflow
catchup=False forever. What history did you silently skip?
Practice →hard · Warehouse · Databricks
Auto Loader vs a COPY into a table every hour. When is streaming the simpler design?
Practice →