Overview
A complete BitTorrent client implementing BEP-3: bencoding/decoding, torrent file parsing, HTTP tracker communication, peer handshake, and concurrent piece downloading with integrity verification.
Built as a CodeCrafters challenge. The interesting engineering is in the download pipeline: pieces are split into 16KiB blocks, requested in parallel across multiple peers using round-robin selection, and verified with SHA-1 before being written to disk.
Nothing novel here — this is a faithful protocol implementation. The value is in understanding how a 20-year-old protocol achieves efficient decentralized file distribution with a surprisingly minimal spec.