Governança Algorítmica e Proteção Integral a Criança: O dever de cuidado das Plataformas sob a Lei Nº 15.211/2025

This paper analyzes the duty of care imposed on digital platforms by Law No. 15,211/2025 for child protection online. It aims to examine the paradigm shift from a reactive model to safety by design, outlining hermeneutic tensions with Article 19 of the Civil Rights Framework for the Internet. The research adopts a qualitative methodology, using a deductive approach and bibliographic-documentary analysis of legislation and jurisprudence. Results highlight the overcome of algorithmic neutrality and the rise of strict liability for service security defects. It concludes that the statute enforces the constitutional absolute priority mandate (Art. 227, CF/88), subordinating the attention economy to the safeguarding of fundamental rights in the digital environment.