Here are seven best practices to protect the integrity of your application:
Use shift-left and DevSecOps strategies. ...
Make applications secure by design. ...
Practice defense-in-depth. ...
User authentication and authorization. ...
Create API gateways. ...
Ensure container security. ...
Secure service-to-service communication.
https://www.styra.com/blog/microservices-security-fundamentals-and-best-practices/