I Improved 15 LLMs at Coding in One Afternoon. Only the Harness Changed

2026-02-13

LLM performance in coding is more dependent on the "harness" (tools managing interactions) than the models themselves. "Hashline," an editing tool, uses content hashes for precise LLM edits, avoiding reliance on perfect content recall. Benchmarking 16 LLMs demonstrated Hashline's consistent superior performance over traditional "Patch" and "Replace" methods.