AI-POWERED SYSTEM DESIGN SIMULATOR

Master System Design. Before the Interview.

Practice on a real-time canvas with instant cost and traffic simulation. Get AI feedback on every design — like a senior engineer in your corner. No credit card to start.

Built for engineers preparing for system design interviews. No credit card required · Free tier forever · Cancel anytime.

50+
SYSTEM DESIGN SCENARIOS
3
ANALYSIS MODES: COST · TRAFFIC · AI
FREE DESIGNS WITH FREE TIER
CORE FEATURES

Everything you need to nail the system design round.

Structured practice with cost, traffic, and AI feedback — not just diagrams.

Interactive canvas

Drag-and-drop system design with 20+ components. Connect APIs, DBs, caches, and see data flow.

Cost estimation

Real-time monthly cost as you design. No more guessing AWS bills.

Load simulation

Stress-test your architecture. Find bottlenecks before the interviewer does.

AI-POWERED FEEDBACK

An AI senior engineer reviewing your design.

Run a deep analysis and get feedback like from a staff engineer — bottlenecks, scaling, security, and clear next steps.

Identifies single points of failure and bottlenecks
Suggests concrete architectural improvements
Scores your design 0–100 like a real interview
HOW IT WORKS

Design. Simulate. Conquer.

Three steps to go from blank canvas to interview-ready system architect. Structured system design practice + AI feedback — not just diagrams.

01

Build Your Architecture

Drag components from the palette — APIs, databases, caches, load balancers, queues — and connect them into your distributed system.

02

Simulate & Estimate

Run load simulations to stress-test your design. Get real-time cost estimates and see exactly where your system breaks under pressure.

03

Get AI Feedback

Trigger deep AI analysis of your design. Get actionable feedback on bottlenecks, single points of failure, and improvement suggestions.

Start free →
WHY MOCKARCH

Not just diagrams — interview-ready practice.

Diagram tools let you draw. MockArch gives you cost simulation, load testing, and AI feedback so you're ready for the real thing.

AI feedback on your design

MockArch: IncludedDiagram tools: Not included

Real-time cost estimation

MockArch: IncludedDiagram tools: Not included

Interview scoring & scenarios

MockArch: IncludedDiagram tools: Not included

Structured interview practice

MockArch: IncludedDiagram tools: Not included
PRICING

Simple, honest pricing.

Start free. Upgrade when you're serious. No credit card required · Cancel anytime.

FREE
₹0
forever
  • Unlimited designs & 9 component types
  • 3 AI quick feedbacks per month
  • Real-time cost & traffic simulation
  • All scenario problems (read & practice)
  • Export as image
Get started free
Most popular
PRO — BEST VALUE

Unlimited AI feedback & interview practice

₹299/mo
Save ~₹1,089 with annual
₹2,499/year
  • Everything in Free
  • Unlimited AI deep analyses
  • Interview scenarios with scoring
  • Export as PNG & JSON
  • Priority support
Upgrade to Pro

Secure payment · Cancel anytime · No long-term contract

FAQ

Common questions

Do I need a credit card to start?
No. You can sign up and use the free tier — unlimited designs, 3 AI quick feedbacks per month, cost and traffic simulation — without entering a card. Upgrade to Pro only when you want more AI analyses.
Can I cancel anytime?
Yes. Pro is month-to-month. Cancel anytime and you keep access until the end of your billing period. No long-term contract.
What's included in the free tier?
Unlimited designs and all component types, cost and traffic simulation, 3 AI quick feedbacks per month, and access to all scenario problems. Export as image. No AI deep analysis or interview scoring on free.
How is MockArch different from Miro or Excalidraw?
Those are diagram tools. MockArch is built for system design interview prep: you get real-time cost estimates, load simulation, and AI feedback that scores your design and suggests improvements — like a staff engineer in the room.
Is my data secure?
Designs are stored securely. We use secure payment processing. We don't sell your data. You can export and delete your work anytime.
How does AI feedback work?
Run a deep analysis on your design and get feedback on bottlenecks, scaling, security, and concrete improvements. Optionally get a 0–100 score similar to a real interview. Pro includes unlimited deep analyses.

Still have questions? Explore the product or start free and see for yourself.

Ready to ace the system design interview?

Join engineers who stopped guessing and started designing with confidence. Start for free in under 60 seconds.

No credit card required · Cancel anytime · Free tier for personal projects