• A type of db that stores file or Binary Large Objects
  • Can’t just use normal db’s b/c they are better suited for fast queries, less storage
    • Big files bloat pages, slow every query
    • replicas and backups copy blobs, huge lag and downtime
    • DB storage costs 10X more than object storage
  • How does Object Storage work?
    • Flat namespace = quick file lookups
    • Immutable writes = no locks or races
    • Redundancy = “11 nines” of durability
    • client GET /file1 -> Metadata service (lookup file) -> stream back to client
  • What should you know for an interview?
    • Large files stored in Object storage, metadata in “traditional” db
    • Examples:
      • Photos/ videos for a social-media or messaging app
      • User-uploaded docs for a file-sharing or collab tool
      • Static web assets (images, CSS, JS) served behind a CDN
      • Log and event archives feeding analytics or security pipelines
      • Backup snapshots and db dumbs for disaster recovery
      • Machine-learning training datasets (images, audio, etc)
  • You can upload directly to your object storage via presigned urls
  • Large files are uploaded in chunks and object storage will “stitch” the file back together
  • Examples of popular Object (BLOB) stores?
    • Amazon S3
    • Google Cloud Storage
    • Azure Blob Storage