Data Engineer · Mid-level · System design

A mobile app sends about a billion events a day. Design a system for collecting and storing these events so that analysts can build reports and product dashboards update within a few minutes.

~10 min by voice

How to approach it

The interviewer checks whether the candidate can design an event pipeline for a real load: estimate the volume, separate a fast path for dashboards from the full history for analytics, and account for the specifics of mobile data: duplicates, late arrivals and schema evolution.

Have you seen this question in a real interview?

Answers0

Avg. score—

Strong—

Practiced0

Topics

data lake streaming

Similar questions

The company wants to move from a classic data warehouse to a lakehouse on object storage. How would you design such a platform, and what trade-offs do you see compared to a traditional DWH? Senior Design a service where users upload CSV files of up to several gigabytes, and the service validates them and loads them into PostgreSQL. How would you build it in Python? Mid-level What's the difference between a data warehouse and a data lake? Junior The business wants a real-time dashboard of revenue and order count, with no more than a minute of delay, and the numbers have to match the daily report. How would you design this system? Senior

Answer by voice

The interviewer will ask this question and listen. Think out loud and ask for a hint if you need one. When you're done, pause or tap “That's my answer”. In about a minute, your score and the points you covered show up here.

Best with headphones · ~10 min