YARP (Yet Another Reverse Proxy) is a high-performance, extensible reverse proxy toolkit for .NET, built on ASP.NET Core. It provides a library and samples for creating custom proxy servers with features including request forwarding, load balancing (random, round-robin, least-requests, power-of-two-choices), active and passive health checks, session affinity (cookie, hash, ARR, custom header), request/response transforms, and telemetry consumption. The architecture is middleware-based, with a pipeline that includes routing, load balancing, session affinity, health checks, and delegation (Http.sys). Configuration is driven by immutable records and supports dynamic reload via change tokens. YARP also includes a Kubernetes Ingress Controller module that watches Ingress, Service, Endpoint, and Secret resources to dynamically configure the proxy. The codebase demonstrates strong engineering practices: extensive unit and functional tests, pluggable policy interfaces, efficient stream copying with telemetry, and a transform builder pattern for declarative request/response modifications. It is actively maintained by Microsoft and used in production scenarios.