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Google·Software Engineer·Technical Phone Screen·Senior

Senior
May 2026

Summary

Interviewed for a data engineering role at Google and got a question on marketing channel attribution. Not much else to say, it was a single focused topic and the conversation stayed pretty narrow.

Questions Asked (1)

Q1

How would you design a system to attribute conversions across multiple marketing channels?

Data ModelingProduct Analytics & MetricsSystem Design
Author's notes

This is one of those problems that sounds straightforward until you actually try to explain it.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the business goals and constraints, then propose a flexible data model that captures user interactions across channels. Discuss trade-offs between different attribution models (e.g., last-click, multi-touch) and outline a scalable system architecture for data collection, processing, and attribution computation.

Pro tip: Emphasize the importance of defining clear success metrics and involving stakeholders early to align on the attribution model, as this is often a product and business decision as much as a technical one.

1. Clarify Requirements

Ask questions to understand the business context, such as which channels are involved, what conversion events matter, and what latency and accuracy requirements exist.

2. Design Data Model

Propose a schema to track user touchpoints and conversions, including identifiers to stitch user journeys across devices and channels.

3. Choose Attribution Model

Discuss options like last-click, first-click, linear, time-decay, or custom models, and explain how to make the model configurable.

4. Outline System Architecture

Describe components for data ingestion (e.g., logs, APIs), storage (e.g., data warehouse), processing (e.g., batch/stream), and serving attribution results.

5. Address Scalability and Trade-offs

Discuss how to handle large data volumes, ensure data quality, and balance real-time vs. batch processing, as well as privacy considerations.

Key Points to Mention

  • User identification and stitching across devices/sessions
  • Attribution models (last-click, multi-touch, etc.) and their trade-offs
  • Data pipeline design for collecting and processing touchpoints
  • Scalability and performance considerations (e.g., distributed processing)
  • Data privacy and compliance (e.g., GDPR, cookie-less tracking)
  • Integration with existing analytics and reporting tools

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.