OpenRouter: Fusion beats DeepSeek-V4-Pro on substance

OpenRouter's Fusion model outperformed DeepSeek-V4-Pro in a head-to-head coding test, delivering a complete, compilable Go rate limit parser with correct edge cases while DeepSeek V4 Pro made basic errors including missing package declarations and logic bugs.

OpenRouter: Fusion wins this head to head because it was better where mistakes actually cost you. In the Go rate limit parser, Fusion delivered a complete, compilable snippet and got the edge cases right: case insensitive header lookup, trimming, rejecting signed and fractional numerics, and parsing both RFC1123 and RFC1123Z. DeepSeek V4 Pro stumbled on basics here — no package declaration, an unnecessary net/http import, and a real logic bug in treating a valid integer value of "0" as invali...