Monibuca/engine is a media streaming server engine written in Go, designed for extensibility through a plugin system. It handles the ingestion (publishing) and distribution (subscribing) of media streams, supporting protocols like RTSP, WebRTC, HTTP-FLV, and RTMP via plugins. The engine manages stream lifecycle through a state machine (waiting for publisher, track availability, publishing, waiting to close, closed), processes audio/video/data tracks with efficient buffering, and provides an HTTP API for stream control and monitoring. Key internals include a custom ring buffer for low-latency frame queuing, a memory pool to reduce GC pressure, and an event bus for inter-component communication. The configuration system supports layered overrides (command line > plugin config > global config > defaults). The architecture emphasizes separation of concerns: core stream management resides in stream.go, track handling in track/, publisher/subscriber logic in publisher/ and subscriber/, and plugins extend functionality without modifying the core. Data flows involve publishers sending media to the engine, which demuxes into tracks stored in ring buffers; subscribers then consume these tracks for retransmission. External dependencies include pion/webrtc for WebRTC, bluenviron/gortsplib for RTSP, and zap for logging. The engine exhibits strong performance optimizations but contains some complexity in state handling and occasional use of unsafe pointers for efficiency.