Artificial Intelligence (AI) has been widely adopted to automate tasks in software development, providing support for code generation, testing, and maintenance. This paper presents a systematic literature review on the role of human critical thinking in the validation of AI-generated code, highlighting the benefits, challenges, and limitations of automation in software engineering workflows. The review identifies that, while AI increases efficiency, reduces errors, and optimizes processes, human oversight remains essential to ensuring quality, ethics, and security in software development. Results indicate that the integration of AI tools with critical human evaluation is fundamental to improving system reliability, particularly in high-stakes domains such as financial technology and safety-critical systems.