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Interactive system design with real-time insights. No static diagrams — real behavior.
Free to start · No credit card required
System design is abstract
Boxes and arrows hide what actually happens under load.
See real behavior, not diagrams
Watch latency spike, queues fill, and failures cascade in real time.
Build intuition faster
Change a slider. See the outcome. Understand the trade-off instantly.
Live system metrics
82ms
Latency
1.2k/s
Throughput
0.3%
Error Rate
43
Queue
218ms
p99
99.97%
Uptime
82ms
Latency
1.2k/s
Throughput
0.3%
Error Rate
43
Queue
218ms
p99
99.97%
Uptime
40+
Interactive concepts
<1s
Feedback loop
3
Complexity tiers
∞
Replays
Interactive Learning
Full simulator on desktop
Build architecture graphs, run simulations, and inject chaos on a larger screen.
See how systems react to latency, load, and failure —
not diagrams, but real behavior.
Build intuition engineers use to explain systems clearly.
82ms
Latency
1.3k/s
Throughput
0.3%
Error Rate
41
Queue Depth
Textbooks describe steady-state systems. They skip the failure cascade when a worker saturates, how a timeout amplifies into a retry storm, or what happens the moment your queue hits capacity.
stable
You cannot see a hot shard from a diagram. You cannot feel queue buildup from a bullet list. These behaviors only emerge when the system is running against real load constraints.
Watch backpressure propagate upstream in real time. See the queue drain when the consumer catches up. Understand throughput, latency, and drops as emergent properties — not memorised definitions.
40+ system design concepts. Each one interactive, each one visual.
Learn by interacting with real system behavior — not diagrams, not slides.
Concepts
And 20+ more in the full simulator:
How traffic cycles across servers evenly
0
Total
0 (0%)
S1
0 (0%)
S2
0 (0%)
S3
Each request cycles S1 → S2 → S3 → S1 regardless of server load. Equal distribution at scale, but no awareness of capacity differences.
Real constraints. Your instincts vs. everyone else's. No Googling. No rubrics. Just thinking.
The Sprint
5 architecture questions. Each one tests a real trade-off — caching, scaling, consistency, failure handling.
The Score
Accuracy, depth, and speed all matter. Your answers are weighted — partial credit, streaks, and bonuses included.
The Rank
See where you stand. A live leaderboard resets weekly — so every sprint is a fresh shot at the top.
Daily Streaks
Show up every day. Streaks compound — miss one and the clock resets.
Time Pressure
Thinking time is limited. Real interviews aren't open-book either.
Weekly Ladder
Leaderboard resets every week. Always a fresh chance to climb.
Real Trade-offs
Questions built from actual system design interview patterns.
Available inside the simulator · Free to try
Pricing
Understand distributed systems deeply — not through slides, but through simulation.
Free
No credit card required.
Premium
Most popularBilled monthly · cancel any time.
All prices in INR. Secure payments via Razorpay.
Stop reading about distributed systems. Start running them — watch failure modes, bottlenecks, and recovery strategies emerge in real time.
40+ Concepts
Load balancers to consensus
Interactive Sims
Sliders, toggles, live data
Real Metrics
Latency, throughput, drops
Build Intuition
Not just memorised theory
40+
System Concepts
3
Complexity Tiers
<1s
Feedback Loop
∞
Replays
Free to start · No credit card required · Cancel anytime