Claude Sonnet 5.5 runs 30% faster with 30% less usage

Anthropic's Claude Sonnet 5.5, the second model in the Claude 5.5 family, is shown fixing a bug in Claude Code. Boris Cherny says it runs 30% faster and uses 30% less usage, and Anthropic's announcement says it runs over 30% faster and costs up to 30% less for most work.