Networking Security and Data Persistence Questions

Covers networking fundamentals and practical implementation across client and cloud environments, data persistence strategies for applications, and security practices to protect data and communications. Networking topics include client side networking libraries and patterns for making and handling requests, error handling, retry and backoff strategies, API design and versioning, and cloud network architecture such as virtual private cloud fundamentals, subnets, route tables, network segmentation, stateful and stateless packet filtering, and ingress and egress considerations. Data persistence topics include local and remote storage choices and trade offs, keyed and relational storage models, object mapping, serialization and deserialization formats, and considerations for consistency, transactions, caching, and schema migration. Security topics include authentication and authorization models, identity and access management, encryption in transit and encryption at rest, key management and secret management practices, secure storage mechanisms on device and server side, certificate and credential handling, secure coding and threat mitigation, principle of least privilege, defense in depth, network security best practices, and operational controls such as rotation and auditing. Interviewers may probe concrete technologies and examples across mobile and backend stacks, tradeoffs between persistence solutions, end to end security design, and how networking and storage decisions affect performance, reliability, scalability, and data protection.