SQL for Quant Interviews
SQL for quant interviews guide covering SELECT, joins, aggregation, windows, time series, data quality, debugging, and practice.
Candidates preparing for data, research, and analytics-style quant screens.
SQL prep is about data questions
Quant SQL prompts usually test whether you can read schemas, join tables, aggregate correctly, handle time, and validate the output.
Fundamentals beat dialect trivia
SELECT, WHERE, GROUP BY, JOIN, window functions, date logic, and null handling cover most interview tasks. Dialect details matter after the query logic is clear.
Concrete example
A trade analysis query may join fills to prices, group by symbol and day, compute PnL, and check that every fill matched the intended price row.
Validation is part of SQL
Check row counts, duplicates, nulls, join cardinality, and timestamp assumptions. A query that runs can still answer the wrong question.
Common mistakes
Candidates often optimize syntax before understanding grain. Define the table grain and target metric before writing a complex query.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.