System Design
Databases & Data Modeling
6 practice questions. Free questions open a full answer guide; the rest unlock with Pro.
- When you start a design, how do you decide between a relational database and a NoSQL store, and how does that choice flow from the data model and access patterns rather than the other way around?
- You're modeling the data for an e-commerce system: customers, orders, line items, products, and inventory. How would you design the schema, and where would you choose to denormalize?Go Pro
- How do you decide between a relational database and a NoSQL store for a new service, and how does that choice change the way you model the data?Go Pro
- A core table with hundreds of millions of rows needs a backward-incompatible schema change — say splitting one column into two, or changing a column's type — while the service stays fully online and deploys roll out gradually across the fleet. Walk me through how you'd ship that change safely.Go Pro
- We have a single Postgres instance that's becoming a bottleneck as the product grows. How would you scale the database, and what trade-offs come with each step?Go Pro
- Design the data model and ingestion path for a service that collects metrics from thousands of servers and lets users query them. What makes this workload different from a typical CRUD app?Go Pro
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