{"slug": "experimented-with-claude-opus-5-5", "title": "Experimented with Claude Opus 5.5", "summary": "A developer reported that Claude Opus 5.5 generated correct Rust code from a spec for $0.09 per final generation, improving the code by switching lookup table values from u32 to u8 for slightly faster benchmarks. The same spec had been used previously on GLM 5.3 Flash and required an ambiguity correction before Opus produced the desired output. The developer noted that DeepSeek V4.1 Flash and GLM 5.3 Flash cost less than a cent per generation and are the most cost-effective for routine work, while Claude Opus 5.5 may be worthwhile for complex or important functions.", "body_md": "Recently I have been doing some **spec-based Rust code generation**. This has given me some correctness and performance improvements, and also off-loads the code maintenance a bit, making my life easier. I decided to try to improve some code with **Claude Opus 5.5**.\n\nThe **spec**, which I had previously used on GLM 5.3 Flash, was interpreted slightly **differently** with Opus. I had to correct an ambiguity in the spec, and then Opus generated the desired code. I don't think the issue was Opus's fault; it seemed to generate **correct code**.\n\nThe **cost** was $0.09 for the final code generation. **Opus improved the code** slightly, using `u8` values in a lookup table instead of `u32`, and the result was slightly faster in benchmarks.\n\nI then did some further work in **DeepSeek V4.1 Flash**, which came out to less than a cent per generation. Basically, if it is possible to use a model like DeepSeek V4.1 Flash or GLM 5.3 Flash, those will be the most cost-effective. For **complex things**, or important functions, **Claude Opus** 5.5 may be worthwhile.", "url": "https://wpnews.pro/news/experimented-with-claude-opus-5-5", "canonical_source": "https://www.dotnetperls.com/2026_9_27_experimented-claude-opus-55", "published_at": "2026-09-27 07:00:00+00:00", "updated_at": "2026-09-27 14:28:45.498348+00:00", "lang": "en", "topics": ["large-language-models", "generative-ai", "ai-tools", "developer-tools"], "entities": ["Claude Opus 5.5", "GLM 5.3 Flash", "DeepSeek V4.1 Flash", "Rust"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/experimented-with-claude-opus-5-5", "markdown": "https://wpnews.pro/news/experimented-with-claude-opus-5-5.md", "text": "https://wpnews.pro/news/experimented-with-claude-opus-5-5.txt", "jsonld": "https://wpnews.pro/news/experimented-with-claude-opus-5-5.jsonld"}}