SYS_STATUS: STANDBYPORT: 443 // SSL_ONREF_X: 12.04REF_Y: 75.820x00FF3E // CORE_NETGRID_SEC: A_04
Live distributed system

Build systems.Survive failures.

SystemCraft is an AI-powered system design interview simulator that makes architecture feel alive before the first question is even asked.

AI feedback
Reasoning + structure
Chaos events
Failures, spikes, reroutes
Replayable
Iterate like an interview
Users
CDN
Load Balancer
App Servers
Cache
Primary DB
Replica
Queue
Servers assembling
Latency
781ms
Throughput
+48%
Health
stable

The Architecture Journey

[STATE]: 01_FOUNDATION
NODE_01

> WHAT IS SYSTEM DESIGN?

A set of trade-offs where latency, cost, reliability, and complexity pull in different directions.

[STATE]: 02_BEHAVIOR
NODE_02

> HOW DISTRIBUTED SYSTEMS BEHAVE

Traffic, queues, caches, replicas, and timeouts shape what the user actually experiences.

[STATE]: 03_CHAOS
NODE_03

> FAILURES HAPPEN

Every architecture eventually sees a node drop, a queue grow, or a database stall under pressure.

[STATE]: 04_SIMULATION
NODE_04

> AI INTERVIEW BEGINS

The interviewer changes the constraints and watches how fast the architecture adapts.

[STATE]: 05_ANALYSIS
NODE_05

> YOU RECEIVE FEEDBACK

Structural issues and reasoning gaps are surfaced with direct, actionable guidance.

[STATE]: 06_MASTERY
NODE_06

> BECOME INTERVIEW READY

Build the muscle memory to explain systems with confidence under realistic pressure.

Core Concepts

Available Scenarios
memory

Distributed Caching

>_desc:

Analyze and implement in-memory data grids to absorb massive read-heavy traffic spikes.

Complexity Level
Live system

See the architecture respond.

One event at a time. Every signal explains what changed, where pressure moved, and why the system recovered.

Live Cluster

Request lifecycle · 8 services

Adapting
Throughput
8.2k req/s
p95 latency
142ms
Error rate
0.3%
Queue size
180
Current event
Cache warmingAdapting

Cold reads briefly reach the primary while popular keys enter memory.

Client
8.2k/s
Gateway
healthy
API
3 replicas
Queue
84 jobs
Cache
94.2% hit
Primary
124ms
Replica
synced
Worker
2 active

Cache

Hit ratio

94.2%

More hits remove database work

Database

p95 latency

124ms

Tail latency reveals saturation

Queue

Queue depth

84 jobs

Depth exposes consumer backpressure

Load Balancer

Request distribution

33 / 34 / 33

Even spread protects every replica

✓
System Ready

Architecture validated

✓Cache configured
✓Failover configured
✓Scaling configured
Ready to begin interview
Your architecture can handle the first constraint.
Launch Interview

Frequently Asked Questions

PWR
SYSTEMCRAFT OS v1.0
_DIR: /GENERAL
Software engineers preparing for mid to senior-level system design interviews at top tech companies.