I engineered Sequitur, a high-frequency trading matching engine written in C++20 and integrated with a concurrent Go network gateway via a 6.29MB bidirectional POSIX shared memory ring buffer. The architecture isolates a pure Price-Time Priority limit order book inside a dedicated, single-threaded execution core pinned to physical silicon via taskset and SCHED_FIFO, completely removing operating system synchronization, context switches, and atomic serialization stalls from the trading hot path. To achieve a peak throughput of 63.9 million operations per second, a mean latency of 15.7 nanoseconds, and a strict P99 tail latency bound of 18.2 nanoseconds, the system utilizes a zero-allocation contiguous object pool that maintains cache locality, alongside a lock-free SPSC egress pipeline that buffers outbound execution reports out-of-band to prevent Head-of-Line blocking. To eliminate the multi-threaded cache-line bouncing trap caused by false sharing, the core trading loop tracks real-time performance indicators using thread-local registers, macro-batching metric updates to an asynchronous logging worker only once every 1,024 orders. This decoupled telemetry engine outputs zero-allocation JSON logs to a memory-resident RAM disk, where a Vector data agent leverages inotify watches to stream data into Grafana Loki and Grafana for real-time, sub-microsecond percentile plotting.