Establishing guidelines for developers to follow when writing secure code

Which best practices and guidelines should developers follow during every stage of the development process to write secure code For example: 1. programming in c# 2. C#-SQL Communication 3. Queue Service 4. SQL Queries 5. In Storing Data to Databasse, Cache Database 6. In communication between front-backend api calls 7. In Dealing with Payloads, user data 8. In Dealing with scripts on Cdns 9. programming In React 10. REACt on CDN communication 11. CDN-API communication