Agentic AI Engineering in Practice: How AI Engineers and Forward-Deployed Engineers Build with Claude Code, Codex, and Gemini

A practical, three-tool guide to the AI-native software development life cycle (SDLC): Plan, Design, Build, Test, Deploy, Maintain, reimagined for agentic coding. In March 2025, a small nonprofit research group called METR published a chart that made many engineering leaders sit up straighter than usual. Working backward through six years of model...