System Design Simulator
Practice real system design interviews without the long essay.
Two ways to practice: run full interview simulations with timed phases, or jump into fast game rounds for short, repeatable reps.
Interview Session Mode
Timed clarifying questions, structured design canvas, and review scoring.
Game Mode
Quick multiple choice, true/false, ordering, and pick-all drills.
Use Both Together
Build speed in game mode, then validate depth in full scenarios.
Pick a scenario
Start a timed session with a real-world data engineering prompt. Filter by domain and role to find the best fit for your practice needs. Some scenarios have linked game decks for targeted practice on specific skills.
Showing 1-6 of 8
Streaming Anomaly Alerts
Design a system that ingests IoT telemetry and triggers anomaly alerts.
Multi-Tenant Analytics Warehouse
Design a multi-tenant analytics warehouse for a B2B SaaS product.
Partner Data Sync with SLAs
Design a system to sync partner data into your platform with strict SLAs and schema drift.
Ticketing Platform Enterprise Data Products Platform
Design a next-generation enterprise data products platform for a ticketing company serving major sports and entertainment organizations. External clients need reliable analytics feeds, near-real-time operational metrics, and self-serve dashboards.
Design an API Rate Limiter
Design a rate limiting service that protects backend APIs from abuse while preserving good experience for legitimate users and tenants.
Build Middleware for 3rd-Party Ticketing
Design middleware that ingests and normalizes ticket inventory and event updates from multiple third-party providers, then serves reliable internal and partner-facing interfaces.
Create a new scenario
LLM-assisted scenario and deck generation based on provided job description.
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Quick Game Mode
Mobile-first rounds with multiple choice, true/false, ordering, and pick-all questions.