Beyond "Vibe Coding": Architecting a Zero-Copy Hybrid C++/Python HFT System

Everyone is drunk on “vibe coding”—prompt a model, get thousands of lines, feel like you shipped something real. That illusion collapses the moment you enter a domain where latency is a P&L variable . In HFT, a single unpredictable pause isn’t a bug—it’s lost edge. I didn’t “use AI to build a trading system.” I used it as a compiler for syntax while taking full ownership of architecture, memory, and failure modes. That distinction is everything. The Real Problem: Latency vs. Intelligence You’re forced into a false trade-off: C++ → deterministic, nanosecond execution, zero tolerance for abstraction overhead Python → flexible, ML-native, but plagued by GIL, GC pauses, and jitter If you pick one, you lose. So don’t pick. The Only Viable Model: Separation of Concerns at the Process Level Not microservices. Not APIs. Not containers. Hard separation of responsibilities at the memory boundary. 1. The Hot Path (C++ — Nervous System) Owns the NIC Ingests raw UDP/WebSocket ticks Normalizes into