I run an auditor that reads trading-strategy repos while I sleep. A 1.5B model is part of it, and for a long time I described that part wrong.

The tool runs five deterministic checks over the source, then hands each finding to a local model with exactly six lines of context and one yes/no question: is this actually true here? Nothing leaves the machine. No API key, no upload, no account. The model is Qwen2.5-Coder-1.5B-Instruct Q4_K_M, loaded through llama.cpp, on a laptop CPU.

The interesting part is not that it works. It is where it stops working, and what I changed once I measured that.

The 48-second constraint

Four model checks on the bundled sample take about 48 to 50 seconds on this laptop. That is roughly twelve seconds per question. The deterministic pass, --no-llm , takes under a second.

Twelve seconds per question is the fact that shaped everything else. You cannot put that inside a loop over every file in a repository. You cannot put it behind a save button.…