[
    {
        "id": "url-shortener-easy",
        "name": "URL Shortener",
        "description": "Build a basic service to shorten URLs with a single backend.",
        "difficulty": "easy",
        "targetRps": 100,
        "durationSec": 60,
        "maxMonthlyUsd": 100,
        "maxP95LatencyMs": 200,
        "requiredAvailabilityPct": 99.0,
        "mustInclude": ["database"],
        "hints": ["Start with a basic backend and persistent storage."]
    },
    {
        "id": "url-shortener-medium",
        "name": "URL Shortener",
        "description": "Scale your URL shortener to handle traffic spikes and ensure high availability.",
        "difficulty": "medium",
        "targetRps": 1000,
        "durationSec": 180,
        "maxMonthlyUsd": 300,
        "maxP95LatencyMs": 150,
        "requiredAvailabilityPct": 99.9,
        "mustInclude": ["database", "loadBalancer"],
        "encouragedComponents": ["cache"],
        "hints": ["Consider caching and horizontal scaling."]
    },
    {
        "id": "url-shortener-hard",
        "name": "URL Shortener",
        "description": "Design a globally distributed URL shortening service with low latency and high availability.",
        "difficulty": "hard",
        "targetRps": 10000,
        "durationSec": 300,
        "maxMonthlyUsd": 1000,
        "maxP95LatencyMs": 100,
        "requiredAvailabilityPct": 99.99,
        "mustInclude": ["cdn", "database"],
        "encouragedComponents": ["cache", "messageQueue"],
        "hints": ["Think about write-path consistency and global replication."]
    },

    {
        "id": "chat-app-easy",
        "name": "Chat App",
        "description": "Implement a simple chat app for small group communication.",
        "difficulty": "easy",
        "targetRps": 50,
        "durationSec": 120,
        "maxMonthlyUsd": 150,
        "maxP95LatencyMs": 300,
        "requiredAvailabilityPct": 99.0,
        "mustInclude": ["webserver", "database"],
        "hints": ["You don’t need to persist every message yet."]
    },
    {
        "id": "chat-app-medium",
        "name": "Chat App",
        "description": "Support real-time chat across mobile and web, with message persistence.",
        "difficulty": "medium",
        "targetRps": 500,
        "durationSec": 300,
        "maxMonthlyUsd": 500,
        "maxP95LatencyMs": 200,
        "requiredAvailabilityPct": 99.9,
        "mustInclude": ["webserver", "database", "messageQueue"],
        "encouragedComponents": ["cache"],
        "hints": ["Ensure you decouple frontend from persistence."]
    },
    {
        "id": "chat-app-hard",
        "name": "Chat App",
        "description": "Design a Slack-scale chat platform supporting typing indicators, read receipts, and delivery guarantees.",
        "difficulty": "hard",
        "targetRps": 5000,
        "durationSec": 600,
        "maxMonthlyUsd": 1500,
        "maxP95LatencyMs": 100,
        "requiredAvailabilityPct": 99.99,
        "mustInclude": ["messageQueue", "database"],
        "discouragedComponents": ["single-instance webserver"],
        "hints": ["Think about pub/sub, retries, and ordering guarantees."]
    },

    {
        "id": "netflix-easy",
        "name": "Netflix Clone",
        "description": "Build a basic video streaming service with direct file access.",
        "difficulty": "easy",
        "targetRps": 200,
        "durationSec": 300,
        "maxMonthlyUsd": 500,
        "maxP95LatencyMs": 500,
        "requiredAvailabilityPct": 99.0,
        "mustInclude": ["cdn"],
        "hints": ["You don’t need full-blown adaptive streaming yet."]
    },
    {
        "id": "netflix-medium",
        "name": "Netflix Clone",
        "description": "Add video transcoding, caching, and recommendations.",
        "difficulty": "medium",
        "targetRps": 1000,
        "durationSec": 600,
        "maxMonthlyUsd": 2000,
        "maxP95LatencyMs": 300,
        "requiredAvailabilityPct": 99.9,
        "mustInclude": ["cdn", "data pipeline", "cache"],
        "encouragedComponents": ["monitoring/alerting"],
        "hints": ["Think about asynchronous jobs and caching strategy."]
    },
    {
        "id": "netflix-hard",
        "name": "Netflix Clone",
        "description": "Design a globally resilient, multi-region Netflix-scale system with intelligent failover and real-time telemetry.",
        "difficulty": "hard",
        "targetRps": 10000,
        "durationSec": 900,
        "maxMonthlyUsd": 10000,
        "maxP95LatencyMs": 200,
        "requiredAvailabilityPct": 99.999,
        "mustInclude": ["cdn", "data pipeline", "monitoring/alerting"],
        "encouragedComponents": ["messageQueue", "cache", "third party service"],
        "hints": ["You’ll need intelligent routing and fallback mechanisms."]
    },
    {
        "id": "rate-limiter-easy",
        "name": "Rate Limiter",
        "description": "Build a basic in-memory rate limiter for a single instance service.",
        "difficulty": "easy",
        "targetRps": 200,
        "durationSec": 60,
        "maxMonthlyUsd": 50,
        "maxP95LatencyMs": 100,
        "requiredAvailabilityPct": 99.0,
        "mustInclude": ["webserver"],
        "hints": ["Use an in-memory store and sliding window or token bucket."]
    },
    {
        "id": "rate-limiter-medium",
        "name": "Rate Limiter",
        "description": "Design a rate limiter that works across multiple instances and enforces global quotas.",
        "difficulty": "medium",
        "targetRps": 1000,
        "durationSec": 180,
        "maxMonthlyUsd": 300,
        "maxP95LatencyMs": 50,
        "requiredAvailabilityPct": 99.9,
        "mustInclude": ["webserver", "cache"],
        "encouragedComponents": ["messageQueue"],
        "hints": ["Consider Redis or distributed token buckets. Account for clock drift."]
    },
    {
        "id": "rate-limiter-hard",
        "name": "Rate Limiter",
        "description": "Build a globally distributed rate limiter with per-user and per-region policies.",
        "difficulty": "hard",
        "targetRps": 5000,
        "durationSec": 300,
        "maxMonthlyUsd": 1000,
        "maxP95LatencyMs": 30,
        "requiredAvailabilityPct": 99.99,
        "mustInclude": ["cache"],
        "encouragedComponents": ["cdn", "data pipeline", "monitoring/alerting"],
        "hints": ["Ensure low latency despite distributed state. Avoid single points of failure."]
    },
    {
        "id": "metrics-system-easy",
        "name": "Metrics System",
        "description": "Create a basic system that collects and stores custom app metrics locally.",
        "difficulty": "easy",
        "targetRps": 100,
        "durationSec": 120,
        "maxMonthlyUsd": 100,
        "maxP95LatencyMs": 200,
        "requiredAvailabilityPct": 99.0,
        "mustInclude": ["webserver", "database"],
        "hints": ["Start by storing metrics as timestamped values in a simple DB."]
    },
    {
        "id": "metrics-system-medium",
        "name": "Metrics System",
        "description": "Design a pull-based metrics system like Prometheus that scrapes multiple services.",
        "difficulty": "medium",
        "targetRps": 1000,
        "durationSec": 300,
        "maxMonthlyUsd": 500,
        "maxP95LatencyMs": 100,
        "requiredAvailabilityPct": 99.9,
        "mustInclude": ["data pipeline", "monitoring/alerting"],
        "encouragedComponents": ["cache"],
        "hints": ["Consider time-series indexing and label-based queries."]
    },
    {
        "id": "metrics-system-hard",
        "name": "Metrics System",
        "description": "Build a scalable, multi-tenant metrics platform with real-time alerts and dashboard support.",
        "difficulty": "hard",
        "targetRps": 5000,
        "durationSec": 600,
        "maxMonthlyUsd": 1500,
        "maxP95LatencyMs": 50,
        "requiredAvailabilityPct": 99.99,
        "mustInclude": ["monitoring/alerting", "data pipeline"],
        "encouragedComponents": ["messageQueue", "cache", "third party service"],
        "hints": ["Think about downsampling, alert thresholds, and dashboard queries."]
    }
]