🏗️For system design rounds

Design at scale,
without freezing

System design rounds reward structure: requirements → API → data model → scale. Interview Assistant walks the structured path with you and prompts you to consider the tradeoffs interviewers grade on.

Questions you'll actually get

Real system design prompts from FAANG, Indian unicorns, and YC-backed startups.

Q.Design Twitter for 100M daily active users
Q.Design a URL shortener (bit.ly) handling 100M req/day
Q.Design WhatsApp / a real-time chat system
Q.Design a distributed rate limiter
Q.Design Uber / ride-matching service
Q.Design a notification system for a global app

A real sample answer

This is the exact kind of response Claude streams in during your interview.

INTERVIEWER ASKED
Design Twitter for 100M daily active users
AI SUGGESTIONconcisedetailedbullets
Start with reads vs writes. 100M DAU × ~10 reads each = 1B reads/day = ~12K QPS read; writes are ~10× lower. So this is a read-heavy system — fan-out on write makes sense. Architecture: tweets table sharded by user_id, timeline cache in Redis per user (fan-out on write populates each follower's cached timeline). For the 1% celebrity-follower problem, fall back to fan-out on read. Eventual consistency on the timeline is acceptable; strong consistency on the tweet itself. Want me to go deeper into the storage layer, the celebrity edge case, or the cache invalidation strategy?

How Interview Assistant helps

Four specific ways the AI adapts to system design rounds.

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Structured walkthrough

Functional requirements → non-functional requirements → API design → high-level architecture → data model → scale considerations. Claude follows the standard rubric so you never miss a section.

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Tradeoffs named explicitly

CAP theorem, SQL vs NoSQL, eventual vs strong consistency, push vs pull, sync vs async — the AI names tradeoffs as it proposes choices, which is exactly what senior interviewers grade on.

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Capacity math on the fly

"100M DAU × 100 reads × 8 hours = ~3.5K QPS read." Back-of-the-envelope numbers ready when the interviewer asks "how much storage?" or "what's the read QPS?"

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Scale story step by step

Start simple, then scale: monolith → sharded DB → read replicas → cache layer → CDN. Claude walks the canonical scale ladder so you don't jump straight to 'microservices and Kafka' before justifying it.

System Design interview playbook

Real candidate advice — what to do beyond just using the AI.

01

Start with requirements, not architecture

First 5 minutes: clarify scope, functional features, scale, and constraints. Jumping to "I'll use Kafka" without this is the #1 way to fail.

02

Draw, even verbally

Describe the boxes: "On the client side, we have… that talks to an API gateway… which routes to…". Interviewers visualize as you talk; if you can't draw, narrate clearly.

03

Name a tradeoff every time you make a choice

For every component, say what you're giving up: "I'll use eventual consistency because we need write throughput; the cost is the user might see their post a few seconds late."

04

Don't pretend you've designed it before

If the system is unfamiliar, say so and ask questions. Interviewers respect 'this is new to me, let me think it through' more than confident wrong answers.

Get Interview Assistant before your next system design round

From ₹1,499 one-time. Lifetime ₹9,999 if you want it forever. 7-day money-back guarantee.

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