Agent Engineering, a new discipline focused on designing, developing, and supervising intelligent AI agents. These agents, powered by Large Language Models (LLMs), are distinct from traditional software as they are autonomous, goal-oriented entities capable of perceiving, reasoning, acting, and learning. The field emphasizes intent-aligned agents built with components like integrated LLMs, adaptive planning, and centralized memory, contrasting with current prompt-based LLM interactions that lack robust abstraction. It highlights the shift from hardcoded logic to orchestrating intelligent systems, emphasizing the need for better specifications, rigorous evaluation, and new professional roles to manage these evolving AI paradigms. The text concludes by asserting that Agent Engineering is a fundamental change in software development, fostering collaborative autonomy between humans and AI.