Tiktok Data Manipulation (SQL/Python) Interview Questions
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Calculate User Registration Date and 7-Day Retention Rate
user_posts +---------+--------------+-----------+ | user_id | posting_date | num_posts | +---------+--------------+-----------+ | 1 | 2023-01-01...
Compute 7-Day Rolling Average of Unique Post Viewers
POST_VIEWS +---------+------------+---------+ | user_id | view_date | post_id | | 101 | 2023-08-01 | 10 | | 102 | 2023-08-01 | 11 |...
Identify Top Discounts and Monitor Code Submissions
Products +------------+----------+-------+----------+ | product_id | category | price | discount | +------------+----------+-------+----------+ | 101 ...
Analyze and Clean European Ecommerce Sales Data
sales +----------+-------------+------------+---------+---------+----------------+ | order_id | customer_id | order_date | country | revenue | product...
Tiktok DS Interview Questions
Scenario: You are provided with two tables: minute_streamed and minute_viewed. The minute_streamed table records each minute of streaming activity, wh...
Compute last-to-previous ad impression gaps
Given impressions(ad_id INT, user_id INT, impression_ts TIMESTAMP) with multiple impressions per (user_id, ad_id), write a single SQL query to return,...
Compute CTR drop with exclusions
Assume today = 2025-09-01. Using ad delivery logs, find advertisers whose CTR in the last 7 days (2025-08-25 to 2025-08-31) dropped by at least 20% re...
Compare SQL counts, windows, and NULL semantics
You’re given two tables. users(id INT, country STRING, created_at DATE) rows: 1 | US | 2025-08-28 2 | US | 2025-08-30 3 | IN | 2025-08-29 4 | BR | 202...
Compute 7-day rolling complaint/order ratio in SQL
SQL only. Given the schema and sample data below, write a single Postgres query (no procedural code) to compute a 7-day rolling complaint-to-order rat...
Calculate valid daily usage with gap constraints
Write Standard SQL to compute, for a given date (use 2025-09-01), each user's total valid usage minutes. Schema and rules: Schema (timestamps are UTC)...
Write SQL for last-7-day metrics without windows
Assume today is 2025-09-01. Use ANSI SQL only and do not use window functions. You may use subqueries, GROUP BY, HAVING, and JOINs. Schema and small s...
Discuss Python mutability, copying, and GIL
In Python, explain the differences between mutable and immutable objects and illustrate how they affect function arguments and container behavior. Des...
Debug a Hive Query for DAU
You are given two Hive tables: users(user_id BIGINT, created_at TIMESTAMP) and events(user_id BIGINT, event_time TIMESTAMP, event_name STRING) PARTITI...
Debug a Hive query
You are given a prewritten Hive SQL query that produces incorrect results. Describe how you would debug it: identify logical errors (e.g., join condit...
Analyze Posting Behavior by Cohort and Date
creator_post +------------+---------+------+ | post_date | user_id | post | +------------+---------+------+ | 2023-01-01 | 111 | 1 | | 2023-01...
Calculate Day-7 Retention Rate from User Post Data
post_activity +---------+------------+-------+ | user_id | post_date | posts | +---------+------------+-------+ | 1 | 2023-01-01 | 3 | | 1 ...
Calculate Monthly Conversion Rate and Average Order Value
page_views +-----------+---------+---------------------+ | user_id | page_id | view_timestamp | +-----------+---------+---------------------+ |...
Calculate Conversion Rate from Ad Clicks to Page Visits
user_events | user_id | event_time | event_type | ad_id | |---------|----------------------|------------|-------| | 1 | 2023-01-01 10:...
Identify Repeat Advertisers from Consecutive Weeks
SUBMISSIONS +--------------+-----------+-----------+ | advertiser_id| ad_id | week_id | +--------------+-----------+-----------+ | A123 ...
Select 10% Users Randomly from User Table
users +----+----------+-------------+ | id | username | signup_date | +----+----------+-------------+ | 1 | alice | 2023-01-02 | | 2 | bob ...