System DesignFlight Simulator
Stop memorizing. Start building. Practice real-world scaling problems with an AI that challenges your architectural decisions—just like a skeptical senior engineer would.
70+ engineers practicing · Free to start
Trusted by engineers preparing for senior roles
Stop Memorizing. Start Engineering.
Traditional interview prep is broken. You wouldn't learn to fly a plane by reading a manual. Why learn system design that way?
The Old Way
- Learning MethodPassive reading & video watching
- Feedback LoopNone or slow (manual review)
- RealismTheoretical diagrams
- RetentionLow (forget after interview)
The ArchSim Way
- Learning MethodActive problem solving & simulation
- Feedback LoopInstant AI analysis & grading
- RealismProduction-grade constraints
- RetentionHigh (muscle memory)
Everything you need to master system design
ArchSim turns complex distributed systems into clear insights you can actually use — helping you track, plan, and grow your systems with confidence.
Realistic Architecture
Design systems with real-world components like Load Balancers, Kafka, and Redis. Map out every dependency with surgical precision.
AI-Powered Insights
Get instant, deep-dive analysis on bottlenecks, single points of failure, and trade-offs in your design.
Real-time Metrics
Visualize latency, throughput, and error rates of your designed system as you inject traffic. Watch your architecture scale or fail under pressure.
Your Path to Architecture Mastery
Design is not about drawing lines between boxes; it's about understanding constraints and making calculated trade-offs.
Choose Scenario
Select from a library of real-world architecture challenges based on top-tier tech interviews.
Design System
Use our production-grade workbench to drag and drop components like Load Balancers, Kafka, and Database Clusters.
Simulate Traffic
Launch your system and inject real-time traffic to see how it scales under pressure.
Get AI Feedback
Receive instant, deep-dive analysis on bottlenecks, single points of failure, and trade-offs.