It's coming up on a year since the models actually changed. Not incremental, a real shift in what AI can do for engineers. In that year the whole landscape has rewritten itself.
The numbers tell it better than words. August 2025: Claude 3.5 Sonnet at 200K context and 49% SWE-bench. August 2026: Claude Fable 5 at 1M context and 95% SWE-bench. Twelve months and the headline numbers more than doubled.
The Model Landscape (August 2025)
Three models mattered for coding.
Claude 3.5 Sonnet (Anthropic) — 200K context, $3/$15 per MTok. 92% HumanEval, 49% SWE-bench Verified. This was the SOTA coding model. No agent mode, no sub-agents, no computer use. The 200K context was considered generous.
