System Design Mock Interview
Design an Online Auction
Work through the five parts of a system design interview one at a time. An AI interviewer asks the questions, then scores your reasoning against an interview rubric.
The interviewer guides you through topics one by one.
The five parts
Each part is a short mock interview. Start anywhere.
1
Problem Exploration / Scoping
Define the core features, boundaries, scale, and non-functional requirements.
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2
High-Level Design
Sketch the services, stores, and asynchronous paths, then justify the boundaries.
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3
End-to-End Design
Trace a representative request through APIs, data, consistency, and failure handling.
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4
Scaling
Find the bottlenecks, partition the workload, and explain the tradeoffs of each scaling move.
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5
Capacity Planning
Turn the assumptions into request rates, storage growth, and an order-of-magnitude deployment plan.
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Your progress
No sessions yet
Finish a part and your best score lands here. Sessions are saved to your account when you are signed in. For the full reference design, read the Design an Online Auction solution.
Problem Exploration / Scoping—
High-Level Design—
End-to-End Design—
Scaling—
Capacity Planning—