How do I choose and run workloads in the cloud?

Service models. *IaaS* (virtual machines, networks), *PaaS* (managed runtimes and databases), *SaaS* (finished software), and *serverless/functions* (pay per execution).

Selection guidance

• Prefer managed services — you operate less and inherit the provider's resilience
• Understand the shared responsibility model: the provider secures the cloud; you secure your configuration, identities and data
• Design for availability zones; adopt multi-region only with a clear recovery or latency requirement
• Apply least-privilege IAM, private networking and encryption by default
• Practise FinOps: tag resources, set budgets and alerts, right-size, and review cost monthly
• Avoid needless lock-in with open standards (containers, SQL, OpenTelemetry) — but don't pay for portability you will never use

Frameworks: the AWS Well-Architected Framework's pillars — operational excellence, security, reliability, performance, cost and sustainability — apply to any cloud.