flowchart LR
    subgraph DeadLinks
        URLs["`[]URL{
        - URLString
        - LastChecked
        - Status
        - DestURLs
        - Pinned
        }`"]
        style URLs text-align:left

        Cleaner -->|"periodically delete where\nnot linked to and not pinned"| URLs

        CheckerWorker -->|getNext| Queue
        Queue -->|iterate over stale| URLs
        CheckerWorker -->|upsert| URLs
    end

    User -->|upsert pinned| URLs
    User -->|notify pinned| Queue
    User -->|query by state| URLs