With the remarkable service delivery, Cloud has succeeded in attaining immense popularity. With three services models, IaaS (infrastructure as a service, Paas (platform as a service) and SaaS (software as a service), we always make a mistake of thinking that IaaS comes first in the evolution. But you’re wrong here! SQS (simple queueing service) was the first service offered by Amazon using cloud in 2004. Soon after, cloud PaaS became the most preferred choice of developers as it eliminates the hassles of managing IT infrastructure of business applications. Why PaaS? Lets consider the simple analogy to gain understanding of PaaS. Before developing an application, developers will analyze the need and functions of the application. They will have to study the platform they require for developing the application and other required equipments. If the developer find the integrated platform, he will code the application accordingly. Now, lets suppose you have an integrated platform equipped with all the underlying necessities. For developers, it was dream come true. It made developing applications more efficient, integrated and excited. Scope of PaaS over other models Despite, IaaS having the ability to allow exibility to the developers for deploying applications with full control, it comes with myriad of hassles related to infrastructure building and operations. On the other hand, SaaS limits the innovations as the developers’ role in SaaS offerings are restrained. Talking about cloud PaaS, it allows developers to innovate more frequently. All developers require is the details of environment such as region, deployment plan and language, the environment is ready and coding is set in action. Main reason of greater scope of PaaS is the costs. It enables developers with pay-as-you-go payment model. PaaS encourages the code over various chains of environments including test, staging, pre-production and production. PaaS platforms are quite resilient as more than one node serve the actual load to maintain high availability. Code and configuration can be replicated across facilities and regions to add the capability of recovery in disaster situations. Drawbacks of PaaS Even though PaaS offers multiple solutions, there are some pitfalls that needs to be addressed by the developers before going forward. Here are some limitations which comes with cloud PaaS:

1. Legacy applications are not supported by PaaS as they don’t quite fit with PaaS environment.
2. PaaS roles out the VMs or machine instances underneath its offering. There is a limit on these machines in terms of computing power such as memory and CPU. Hence, a challenge of application load to which PaaS can scale will have to be encountered.
3. One of the major inhibitors of PaaS is provider lock-in. Simple transportability of code amongst providers is far from reality. To replace the provider for performance or cost, you will need to plan and invest, as the code in one platform will not work in another.
4. It’s imperative that the enterprises follow providers’ service roadmap as strenuous situations could arise if the provider stops supporting specific language platform or associated tools.