More in Analytics & Metrics — page 14
How do you handle timezones for a daily global sales report?
This tests your understanding of time data modeling and business requirements. A good answer stores events in UTC with a timezone identifier, then converts to the business's chosen 'day' at query time. A red flag is storing local time without context.
How would you implement Change Data Capture (CDC)?
Tests your grasp of data replication trade-offs. A great answer compares log-based CDC (low impact, complete) with query-based methods (higher impact, misses deletes), and recommends log-based CDC for its minimal production impact.
Propose a multi-touch attribution model and its data pipeline
Tests your grasp of attribution models and their data engineering needs. Propose a rule-based model (e.g., time-decay), outline the data pipeline for it, and acknowledge privacy-driven signal loss. A red flag is ignoring the challenge of identity resolution.
Transform a time series for a supervised learning model?
This tests your ability to reframe a time series problem for tabular models. A great answer explains creating features from lags, rolling windows, and calendar data, then emphasizes using a time-aware validation split. A red flag is forgetting validation.
Find leading indicators for long-term churn
This tests your ability to translate a business problem into a data investigation. A strong answer defines churned vs. retained cohorts, hypothesizes key early behaviors, and compares their frequency to find a leading indicator.
Calculate Daily Active Users (DAU) with SQL
This tests product sense and SQL fundamentals. Define 'active' with a core product action, describe the event data needed, then write a COUNT(DISTINCT user_id) query. A red flag is writing SQL before defining the business logic for 'active'.
Client-Side vs. Server-Side Event Tracking
Tests your grasp of data integrity and architectural trade-offs. A great answer defines both, favors server-side for reliability (avoids ad-blockers), but notes client-side's richness for UI events. A red flag is presenting them as equal choices.
How would you build a SQL query for a conversion funnel?
Tests your ability to translate a business need into a technical SQL solution. A good answer uses CTEs or LEFT JOINs to model sequential steps, counts users at each stage, and discusses attribution.
Trade-offs: Bundled vs. Warehouse-Native Product Analytics
This tests your grasp of modern data stack architecture. A great answer weighs trade-offs in data control, cost, query flexibility, and team capabilities. A red flag is ignoring total cost of ownership and engineering overhead for a warehouse-native setup.
Why don't analytics and backend user counts match?
This tests your systematic debugging and understanding that 'user' has different definitions. A good answer first defines 'user' in each system, then investigates tracking implementation, timing differences, and filtering.
Client-side vs. Server-side Event Tracking: When and Why?
This tests your grasp of data reliability and security trade-offs. A good answer defines both, contrasts reliability (ad blockers) vs. implementation ease, and uses a critical event like "Payment Processed" to justify server-side's accuracy.
Architect a Multi-Touch Attribution System
This tests your grasp of modern data challenges like signal loss. A good answer discusses data ingestion, identity resolution, and model trade-offs. A red flag is focusing only on the algorithm and ignoring the data pipeline's fragility.
Calculate a 3-step user onboarding funnel with SQL
Tests your ability to translate a business need into a robust data query. A great answer clarifies funnel logic (attribution, timing), defines the user cohort, finds each user's first event for each step, and then calculates conversion.
Implement an A/B test for a new checkout flow
This tests your ability to design a robust, stateful system for experimentation and data analysis. A great answer details user bucketing, consistent variant assignment across devices, and the SQL query structure for analysis.
What is the 'multiple comparisons problem' in A/B testing?
Tests your grasp of statistical pitfalls in large-scale A/B testing. Define the problem (inflated false positives), explain the business risk (wasted effort), and propose a mitigation like Bonferroni correction.
Visualizing Load Time vs. Session Duration with a Third Variable
Tests your ability to visualize correlation and add dimensions. A great answer suggests a scatter plot for the initial relationship, then uses color to segment by the categorical third variable (network type).
.png&w=1600&q=75)
Cohort Analysis for a New Onboarding Flow
Tests applying analytics to measure impact. Define a cohort, then compare a pre-launch (Dec) vs. post-launch (Jan) acquisition cohort, tracking retention over time. A red flag is using aggregate metrics, which hide the true impact of the change.
How would you visualize a complex, multi-stage user funnel?
Tests product sense and data viz literacy. A good answer proposes a Sankey/Alluvial diagram to show non-linear flows, explains how it visualizes drop-off and re-entry, and notes the data needs. A red flag is just suggesting a better standard funnel chart.
Design a GDPR 'Right to be Forgotten' System
Tests your ability to design a verifiable data deletion system. A good answer outlines an index metastore, an orchestrated workflow, and auditing. A red flag is focusing only on the primary database, ignoring the data lake, warehouse, and caches.
Design an analytics event payload for a button click
This tests your data modeling for analytics. A good answer includes the event name, user ID, and timestamp, then adds contextual and user properties. A red flag is forgetting the user ID or suggesting dynamic property names, which breaks segmentation.