AI Dev Stack

Claude 3.5 Sonnet hit 49% on SWE-bench Verified with a minimal agent scaffold: two tools, one prompt, maximum model control. Here's the exact architecture Anthropic used and why tool design matters as much as model capability.

Anthropic's "think" tool gives Claude structured reasoning checkpoints during execution. It delivered 54% improvement on policy-heavy tasks and 1.6% on SWE-Bench. Here's when to use it—and when to skip it.

Anthropic's Claude Code runs in terminal, IDE, browser, and mobile with session portability across all surfaces. Same context, different environments.

Anthropic's multi-agent research system uses Claude Opus 4 as orchestrator with Sonnet 4 subagents, achieving 90% better performance than single agents. Here's how they built it, the eight prompting principles that emerged, and why production was harder than the prototype.