Architectural Patterns for a 5.5M msgs/sec Market Data Parser in C++20 Processing raw market data feeds (like NASDAQ ITCH 5.0 or NSE FO) requires strict adherence to low-latency principles. Recently, I built a C++20 parser to ingest these feeds, normalize them, and manage a Limit Order Book (LOB). By strictly controlling memory allocation and maximizing CPU cache locality, the parser achieves a