This article is especially for those who work with web development and are just starting out. We are going to look at some relevant points so that we can have our applications more secure and free from risk. To do this, we need to take the following points into account: 1. To begin with, we should always make sure that our sites are using https certificates and not HTTP. This encrypts communication between the user's browser and the server, protecting against data interception. 2. For applications/websites that in some way receive data input from the user, we should always validate data input such as forms, url parameters, cookies, etc. This helps prevent injection attacks such as SQL injection and XSS (Cross-Site Scripting). 3. Use parameterized queries or ORM (Object-Relational Mapping) to avoid SQL injection. Don't build SQL queries by concatenating strings directly with data provided by the user. This avoids SQL injection. 4. When displaying user-supplied data on your site, always escape special characters to avoid XSS attacks. Use functions specific to the language/framework you are using to perform this task. 5. Ensure that your applications grant only the minimum necessary privileges to users or processes. For example, don't give administrator access to regular users. This is called the Principle of Least Privilege. 6. Implement strong password policies for your users, requiring a combination of uppercase letters, lowercase letters, numbers and special characters. Consider using two-factor authentication (2FA) whenever possible. 7. Keep your software updated regularly, including the operating system, web server, database and any libraries or frameworks you are using. Updates often fix known security vulnerabilities. 8. Implement measures to protect against distributed denial of service (DDoS) attacks, such as limiting the rate of requests, using DDoS mitigation services and properly configuring firewalls. 9. Always validate the files uploaded by users to ensure that they meet the expected criteria, thus avoiding malicious file upload attacks. 10. Implement appropriate access controls to restrict access to sensitive resources to authorized users only. This can include authentication, authorization and auditing of access. 11. Keep detailed logs of system activity and network traffic to quickly detect and respond to possible security breaches. Implement alerts for suspicious events. 12. Keep detailed logs of system activity and network traffic to quickly detect and respond to possible security breaches. Implement alerts for suspicious events. 13. Perform regular security tests on your application, including penetration tests, vulnerability scans and code audits, to identify and correct potential security problems. 14. Regularly back up your data and regularly check the integrity of backups. This helps mitigate damage in the event of a security breach or data loss. Remember that in the digital world no one is safe, hence the importance of constantly updating our websites and systems.