DeepSeek V4 Pro 0813 vs Claude Fable 5 on DeepSWE: Cost, Coding, and Routing

The blog post compares DeepSeek V4 Pro 0813 and Claude Fable 5 on the DeepSWE benchmark, finding that DeepSeek V4 Pro 0813 is 90x cheaper and achieves comparable or better performance with multiple attempts.

A cascade routing strategy (Pro first, escalate to Fable) solves 82.7% of tasks at $8.28 each, outperforming Fable alone.