Scaling a web applications can be easy for simple CRUD software running when you use Platform as a Service Clouds (PaaS). But if you need to deploy a complex software, with many components and a lot users, you will need have a mix of cloud services in PaaS, SaaS and IaaS layers. You will also need knowledge in architecture patterns to make all these software components communicate accordingly.
In this article, we share our experience of using cloud services to scale a web application. We show usage examples of load balancing, session sharing, e-mail delivery, asynchronous processing, logs processing, monitoring, continuous deployment, realtime user monitoring (RUM). These are a mixture of development and system operations (DevOps) that improved our application availability, scalability and performance.