Security, Cost Management & Architecture Patterns

Shared Responsibility Model

Provider secures the cloud (physical/infrastructure); customer secures what's IN the cloud (access controls, app code, data permissions). A misconfigured public storage bucket is a customer-side failure, not a provider one — the split shifts by service model (IaaS vs. SaaS).

High Availability vs. Disaster Recovery

HA prevents downtime from routine component failures via redundancy across zones. DR recovers from a catastrophic, larger-scale failure (a whole region down, major data loss) via backups and a documented recovery plan. Complementary, not interchangeable.

Cost Optimization & Pricing Models

Pay-as-you-go shifts infrastructure cost from upfront capex to ongoing, usage-based opex — but requires ongoing attention (right-sizing, removing unused resources) since costs can silently grow. Reserved/committed-use pricing trades flexibility for a discount on predictable, steady-state workloads; on-demand suits unpredictable ones.

Vendor Lock-In & Multi-Cloud

Deep reliance on one provider's proprietary services accelerates development but raises future switching cost. Multi-cloud reduces that risk (and single-provider outage exposure) at the cost of more operational complexity spanning multiple providers' distinct APIs/tooling.

Serverless, Edge Computing & IaC

Serverless (Lambda, Cloud Functions) abstracts servers away entirely — pay per execution, scales to zero. Edge computing processes data closer to where it's generated/consumed, reducing latency versus a centralized data center (CDNs are a narrower version of this for static content). Infrastructure as Code (Terraform, CloudFormation) manages infrastructure via version-controlled config files instead of manual console clicks — bringing code-review and repeatability to provisioning.

Managed Services

A managed database (AWS RDS) handles patching/backups/failover for you — you still configure and use it, but skip the operational burden a self-managed database on a raw VM would require. This managed-vs-self-managed tradeoff recurs across nearly every cloud service category.