Data security is a critical aspect of full stack application development. To ensure security, I follow several practices. Firstly, I implement appropriate authentication and authorization mechanisms to control access to sensitive data. This includes using techniques like role-based access control (RBAC), implementing secure login mechanisms, and enforcing strong password policies. Secondly, I employ encryption techniques to protect data at rest and in transit. For example, I utilize HTTPS for secure communication and store sensitive data like passwords in hashed or encrypted format. Thirdly, I sanitize user input to prevent common security vulnerabilities like SQL injection and cross-site scripting (XSS) attacks. I use parameterized queries, input validation, and output encoding techniques to mitigate these risks. Additionally, I regularly update and patch software components to address any known vulnerabilities. By adhering to these security practices, I have ensured the integrity and confidentiality of data in my previous full stack projects.