// Resilience

Every cloud project starts with requirements. In this episode, Chris explores the critical pillars of cloud architecture: resilience (SLA, RTO, RPO, MTTR, MTBF), scalability, performance, and cost. Learn why defining requirements upfront—before drawing architecture diagrams—is essential, and how the same on-premises thinking about availability translates directly into the cloud.

Cloud design patterns are abundant and well-documented on the Azure Architecture Center — from established patterns like cache-aside and materialized view to cloud-native ones like circuit breaker and health endpoint monitoring. This Azure Mythbusters episode tours the full pattern catalogue and deep-dives four key patterns: cache-aside, circuit breaker (open/half-open/closed states), health endpoint monitoring, and materialized view in CQRS/event sourcing scenarios.

Moving workloads to Azure does not eliminate management decisions — scalability, resilience, and high availability all require deliberate configuration. This Azure Mythbusters episode contrasts scale-out via VM Scale Sets and auto-scale rules with scale-up by increasing VM SKU size, explains availability sets and availability zones, and shows how PaaS services like Azure Functions still require you to choose the right plan and design cross-region resilience with Traffic Manager.

Requirements remain essential when migrating to or building on Azure — from availability SLAs and RPO/RTO targets to compliance, data sovereignty, and cost. This Azure Mythbusters episode uses composite SLA calculations and Azure Architecture Center reference architectures to show how under- or over-specifying requirements directly shapes your design, region strategy, and overall cost.

In my spare time, I work on a pet project called Theatreers. The aim of this is a microservice based platform focused on Theatre / Musical Theatre (bringing a few of my passion areas together). I've recently re-architected the project to align to a multi-region serverless technology stack.

Scalability is one of the common areas where I have seen common misconceptions, when customers begin building on the platform.

I mentioned in Building Solutions in the Cloud that I would be writing a series of blog posts on the areas of risk that I have seen since I have been providing guidance around Azure. In this post, I will provide some thoughts on how you can consider resilience within the context of your own solution or application.

By now, we should be aware of the benefits that the cloud can bring to any individual or organisaton. There are plenty of case studies, talking about the scalable, flexible and economic benefits. Companies see the cloud as a differentiator, and utilise it to disrupt and innovate in their respective markets. Gartner predicts that in 2016 the total public cloud market is due to increase by 16%. But, Chris - You're starting a blog about technology. Why are you talking to me about customer case studies and market fact? Why? Context.