Fastest coding AI model introduces new bug, Qwen3.6 Coding deemed best

A developer tested four local coding AI models on a real-world FastAPI bug, finding that the fastest model, Qwen3 Coder Fast, introduced a new bug while fixing the original one. The model Qwen3.6 Coding was deemed the best performer, correctly addressing all aspects of the bug, including database and index cleanup, and even identifying additional edge cases. This experiment led the developer to prioritize correctness and production readiness over raw speed when evaluating coding models. AI

IMPACT Shifts focus from raw speed to production-readiness for coding AI models.

RANK_REASON Developer's personal benchmark and opinion piece on evaluating coding models.

Read on Medium — AI coding tag →

• BM25
• Faiss
• FastAPI
• GLM 4.7 Flash
• MacBook Pro M4 Pro
• North Mini Code 1.0
• Ollama
• PostgreSQL
• Qwen3.6 Coding
• Qwen3 Coder Fast

• product
• other

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