Tech-specific interview prep

System Design Interview Questions and Evaluation Rubrics

Practice system design through requirements, scale, interfaces, data, reliability, observability, and explicit tradeoffs.

Best for: Mid-level through staff software engineers preparing for architecture interviews.

What to prepare

  • Requirements
  • Capacity
  • APIs and data
  • Reliability
  • Tradeoff communication

Practice with a rubric

System Design interview questions and strong-answer signals

Answer each question aloud before opening the rubric. The goal is not a single perfect answer; it is clear reasoning grounded in production constraints.

  1. 1

    Design a notification system supporting email, push, and SMS at global scale.

    What this tests

    Requirements, fan-out, preferences, delivery semantics, and provider failure.

    Strong-answer signals

    • Clarifies urgency and ordering
    • Separates orchestration from providers
    • Handles retries, deduplication, and observability
  2. 2

    Design an audit-log platform for regulated customers.

    What this tests

    Immutability, access control, retention, search, and evidence integrity.

    Strong-answer signals

    • Defines threat model
    • Separates write path from indexing
    • Explains retention and tenant isolation
  3. 3

    Design a feature-flag service used on every request.

    What this tests

    Read latency, consistency, rollout safety, and control plane separation.

    Strong-answer signals

    • Optimizes the data plane
    • Defines cache invalidation
    • Handles kill switches and stale configuration
  4. 4

    How do you decide which component to scale first?

    What this tests

    Capacity estimation and bottleneck identification.

    Strong-answer signals

    • Uses expected workload
    • Identifies critical resources
    • Includes load testing and cost

From guide to deliberate practice

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Frequently asked questions

What should I study for a System Design interview?

Prioritize Requirements, Capacity, APIs and data, Reliability, Tradeoff communication. Connect each concept to production decisions, failure modes, and work you can explain from direct experience.

How should I use the strong-answer signals?

Use them as a self-review checklist after answering aloud. They are not a script and strong solutions can take different approaches when their tradeoffs are explicit.

Should I memorize these answers?

No. Practice a repeatable reasoning process: clarify requirements, state assumptions, compare options, choose deliberately, and explain how you would verify the result.