HashiCorp Vault and Kubernetes offer various methods for integration, including the Vault Sidecar Agent Injector, the Vault Container Storage Interface (CSI) provider, and the Vault Secrets Operator. Each method has its own design considerations, such as secret projections, scope, types, definition, encryption, governance, updates and rotation, caching, and auditability. The similarities between these methods include simplifying secret retrieval and exposing secrets to pods without changing application logic. However, there are differences in how they approach this task, including the use of sidecar containers, daemonsets, and Kubernetes Operators. Understanding these differences is crucial for choosing the best method for a specific use case. Additionally, considering factors such as secret scope, types, definition, encryption, governance, updates and rotation, caching, and auditability can help in designing an effective secrets management strategy in Kubernetes environments.