Parallel, resumable S3 listing for very large buckets.
swath divides an unknown S3 keyspace into guessed ranges, corrects the guesses while it lists — splitting overloaded ranges so idle workers can take the other half — and writes JSONL, TSV, or crash-resumable Parquet. It never reads object contents, and --concurrency is a ceiling, not a target.
Why parallel listing is a guessing problem, the range algebra that keeps splits safe, and where swath honestly loses.
One recorded listing of s3://noaa-gestofs-pds, rendered from its 89,230-event trace: replay, seed distribution, mechanism ledgers.