Show HN: I built a concurrent BitTorrent engine in Go to master P2P protocols https://ift.tt/0g9qX8A

Show HN: I built a concurrent BitTorrent engine in Go to master P2P protocols I’ve always used BitTorrent, but I never understood the complexity of peer-to-peer orchestration until I tried to build it from scratch. I wanted to move beyond simple "Hello World" projects and tackle something that involved real-world constraints: network latency, data poisoning, and the "Slow Peer Problem." Key Technical Challenges I Solved: Non-Blocking Concurrency: Used a worker pool where each peer gets its own Goroutine. I implemented a "Stateless Worker" logic where if a peer fails a SHA-1 hash check or drops the connection, the piece is automatically re-queued into a thread-safe channel for other peers to pick up. Request Pipelining: To fight network RTT, I implemented a pipeline depth of 5. The client dispatches multiple 16KB block requests without waiting for the previous one to return, ensuring the bandwidth is fully saturated. The Binary Boundary: Dealing with Big-Endian logic and the 68-byte binary handshake taught me more about encoding/binary and byte-alignment than any textbook could. Zero-Trust Data Integrity: Every 256KB piece is verified against a "Golden Hash" using crypto/sha1 before being written to disk. If a single bit is off, the data is purged. The Specification: I’ve documented the full spec in the README, covering: Reflection-based Bencode Parsing. Compact Tracker Discovery (BEP-0023). The Choke/Unchoke Protocol State Machine. Data Granularity (Pieces vs. Blocks). Repo: https://ift.tt/gesEVZH I’d love to get feedback from the community on my concurrency model and how I handled the peer lifecycle. February 14, 2026 at 09:44PM