• BitTorrent-style content distribution on raw POSIX sockets with zero dependencies; a control / data-plane split keeps a 2-node tracker cluster holding metadata only while 512 KiB pieces move peer-to-peer, with idempotent op-based replication that self-heals on reconnect and transparent fail-over via RPC retry and session replay.
• Rarest-first scheduling over a multi-connection pool with per-piece SHA-1 verify-before-commit; O(1)-in-file-size memory via positional I/O and streaming hashes — a 200 MB transfer in ~7 MB RSS. Verified clean under ASan / UBSan / LeakSanitizer.

C++17 · POSIX sockets · op-based replication · SHA-1

• Interactive Unix shell built directly on process-management primitives: core built-ins, I/O redirection, arbitrary-depth pipelines, background job control, full signal handling, tab completion, and persistent navigable history.

C++17 · fork / exec · pipes · signals

• Encrypted command-and-control between a Mission Control Center and a drone fleet; hand-implemented 2048-bit ElGamal, HMAC-SHA256, and AES-256-CBC for mutual authentication, session- and group-key establishment, and fleet-wide broadcast — sub-500 ms handshake after key generation.

C++17 · ElGamal 2048-bit · HMAC-SHA256 · AES-256-CBC

• Kerberos-inspired authentication resilient to single-authority compromise via a 2-of-3 Schnorr multi-signature across distributed Authentication / Ticket-Granting servers; AES-256-CBC tickets; ships attack simulations for key leakage and offline-authority compromise.

Python · Schnorr multi-signatures · AES-256-CBC · threshold cryptography

• Stateful, symmetric-key secure-communication protocol between a server and multiple clients, designed to hold up in a hostile network environment.

Python · symmetric-key cryptography · session state

• Maintained the relational cargo-logging database for Oil Jetty No. 8 on the port's Linux servers — wrote SQL and PL/SQL stored procedures and triggers to record, reconcile, and audit consignment and vessel data, enforcing validation and referential integrity across high-volume daily entries.