Answer the following engineering fundamentals questions: 1) Compare RDBMS and NoSQL databases: key trade-offs (schema, transactions/ACID, consistency, scaling, query flexibility), and when you would choose each. 2) Explain virtualization vs containerization: how VMs differ from containers, and what problems Docker solves. 3) What is Kubernetes used for if you already have Docker? Explain what Kubernetes adds (scheduling, service discovery, autoscaling, rollout/rollback, self-healing). 4) Why is Python often slower than C++ for CPU-bound work? List practical ways to speed up Python code and when each approach is appropriate.