Self-contained cuckoo filter implementation with exact membership tracking and low false positive rate. Used for efficient compressed account filtering in the Geyser plugin. Features configurable hasher, storage backend, and atomic operations for concurrent access. Zero external dependencies beyond byteorder and rand, making it highly reusable in any project requiring probabilistic set membership.

Thread-safe token bucket rate limiter using async primitives. Implements configurable capacity and refill rate with atomic counters for high-performance tracking. Designed for limiting requests per connection in network services. Minimal dependencies (only tokio and std) with clear separation of concerns - can be extracted as a standalone crate for any async service needing rate limiting.

Load-aware channel wrapper that tracks queue size and provides metrics for monitoring channel load and backpressure. Built atop Tokio channels with atomic counters for queue metrics. Enables observability in asynchronous systems by exposing current/peak queue sizes. Minimal internal dependencies (only tokio::sync::watch and std::sync::atomic) making it easily adaptable to other async contexts.

Utility for watching directory changes to enable hot-reloading of TLS certificates or configuration. Uses the notify crate for cross-platform file system events with async callback handling. Features debouncing to prevent excessive reloads during file writes. Self-contained with clear interface (watch directory, handle changes) - suitable for any service requiring dynamic configuration updates without restart.