Anthropic quietly shipped Claude Opus 5 last week. Not a flashy announcement, but the numbers caught my attention: roughly 33% cheaper than Opus 4, better at code generation, and supposedly more reliable with tool calling.
I run a small cross-border e-commerce operation where we process product data from dozens of suppliers, generate multi-language descriptions, and manage order workflows. AI is already part of that pipeline. So I spent a weekend porting some of our codebase to Opus 5 and comparing it against what we were using.
This post covers three things: code generation quality, agent orchestration behavior, and whether the price cut actually changes how you'd design a system.
Multi-File Code Generation
The first test was practical. I needed a currency exchange microservice that caches rates, handles fallbacks, and exposes a clean API. No novel problem, but the kind of task where a model either saves you time or wastes it with hallucinated imports.
