PennCloud

PennCloud replicates the core functionality of Google Drive and Gmail — file uploads and downloads, sending and receiving email both within the platform and to external addresses. Under the hood, everything runs on a custom distributed key-value store modeled after Google's BigTable, with data replicated across primary and secondary nodes. Each node checkpoints its state to disk and maintains an operation log, so the system recovers cleanly from failures. We also snuck a multiplayer Blackjack game on top of the storage layer, then deployed the whole thing on AWS.