AI System Design Interview Simulator

Practice architecture decisions,
not just diagrams.

Reason through realistic tradeoffs, model infra costs, and test for resilience with senior-level AI critique. Built for staff and senior engineering candidates.

stacksScenario library (easy free; full on Pro)
paymentsLive cost & traffic simulation
psychologyAI deep analysis (Pro)
hub

Architecture Score

84

Single Point of Failure

Detected at Load Balancer L1

Estimated Infra Cost

$14,200 /mo

Latency Metrics

Everything you need to reason through system design tradeoffs

schema

Model realistic systems

Connect APIs, queues, and databases with precise relationship mapping. Define throughput, payload sizes, and read/write ratios.

cable
monitoring

Simulate scale & cost

Identify bottlenecks before you build. Our engine calculates multi-region data transfer and operational costs at high-scale.

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Senior-level AI critique

Get instant feedback on single points of failure, data consistency risks, and over-engineering tendencies.

Your use of Cassandra for this transactional workload may lead to tombstone issues during heavy deletions...
01

Choose a scenario

Select from high-scale distributed systems like Uber-lite, global chat, or high-throughput payment gateways.

02

Build and simulate

Drag-and-drop components, map data flows, and run the simulator to see latency metrics and cost estimates.

03

Review and iterate

Analyze AI feedback and refine your architecture. Watch how your scores change as you resolve bottlenecks.

AI Analysis Reportv4.2.0-stable

Reliability

92%

Scalability

98%

error

Potential Over-engineering

Kubernetes for a simple worker tier might be excessive; consider Serverless if load is bursty.

warning

Consistency Risk

Your Redis cache layer lacks a TTL strategy for the Auth tokens, leading to staleness.

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Instant AI Review of your technical architecture

Stop guessing if your design scales. Our model is trained on thousands of staff-level design documents and real-world post-mortems.

  • check_circleDetects single points of failure
  • check_circleFlags over-engineered systems
  • check_circleScores scaling, cost, and resilience
  • check_circleRecommends next-step improvements

Your system design edge starts here

Start free, then upgrade for every scenario difficulty, AI deep analysis, and unlimited saved designs.

Free

₹0/mo
  • checkUp to 3 saved designs
  • checkFull component palette
  • checkReal-time cost & traffic simulation
  • checkRule-based standard analysis (automated checks)
  • checkEasy interview scenarios (timed practice & scoring)
  • checkExport canvas as image
Get started free
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Pro

₹299/mo

Save ~₹1,089 with annual · ₹2,499/year

  • check_circleEverything in Free
  • check_circleUnlimited saved designs
  • check_circleAll scenario difficulties (medium & hard unlocked)
  • check_circleUp to 20 AI deep analyses per calendar month (UTC). Resets at 00:00 UTC on the first day of each calendar month.
  • check_circleExport as PNG & JSON
  • check_circlePriority support
Upgrade to Pro

Walk into your next system design interview with real reps behind you.