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Design a Paste Bin Service

URL & Paste ServicesEasy1:30

Design a text paste sharing service similar to Pastebin or GitHub Gists. Users create pastes with plain text or code, receive a unique shareable link, and anyone with the link can view the paste. The system should support 5 million active users creating 10 million pastes per month, with a 5:1 read-to-write ratio.

In your 90-second answer, cover: - High-level architecture and API design - How you generate unique paste URLs - Storage strategy for paste content (which can range from 1 KB to 10 MB) - How you handle the read-heavy traffic pattern

Constraints: pastes are immutable once created, average paste size is 10 KB, pastes expire after 6 months by default.

How to approach it

  • Hint 1

    Separate metadata (title, expiration, language) from content -- they have different access patterns and storage needs.

  • Hint 2

    Content-addressable storage (hash of content as key) can deduplicate identical pastes and save significant storage.

  • Hint 3

    A CDN or cache layer in front of paste retrieval handles the read-heavy pattern efficiently since pastes are immutable.

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