Interview Series: Four Questions With … Hammad Rajjoub

Greetings and welcome to the 43rd interview in my series of chats with thought leaders in the “connected technologies” domain. This month, I’m happy to have Hammad Rajjoub with us. Hammad is an Architect Advisor for Microsoft, former Microsoft MVP, blogger, published author, and  you can find him on Twitter at @HammadRajjoub.

Let’s jump in.

Q: You just published a book on Windows Server AppFabric (my book review here). What do you think is the least-appreciated capability that is provided by this product, and what should developers take a second look at?

A: I think overall Windows Server AppFabric is an under-utilized technology. I see customers deploying WCF/WF services yet not utilizing AppFabric for hosting, monitoring and caching (note that Windows Server AppFabric is a free product). I will suggest all the developers to look at caching, hosting and monitoring capabilities provided by Windows Server AppFabric and use them appropriately in their ASP.Net, WCF and WF solutions.

The use of distributed in-memory caching not only helps with performance, but also with scalability. If you cannot scale up then you have to scale out and that is exactly how distributed in-memory caching works for Windows Server AppFabric. Specifically, AppFabric Cache is feature rich and super easy to use. If you are using Windows Server and IIS to host your applications and services, I can’t see any reason why you wouldn’t want to utilize the power of AppFabric Cache.

Q: As an Architect Advisor, you probably get an increasing number of questions about hybrid solutions that leverage both on-premises and cloud resources. While I would think that the goal of Microsoft (and other software vendors) is to make the communication between cloud and on-premises appear seamless, what considerations should architects explicitly plan for when trying to build solutions that span environments?

A: Great question! Physical Architecture becomes so much more important. Solutions needs to be designed such that they are intrinsically Service Oriented and are very loosely coupled not only at the component level but at the physical level as well so that you can scale out on demand. Moving existing applications to the cloud is a fairly interesting exercise though. I will recommend architects to take a look at the Microsoft’s guide for building hybrid solutions for the cloud (at

More specifically an Architect, working on a hybrid solution, should plan and consider following (non-exhaustive list of) aspects:-

  • data distribution and synchronization
  • protocols and payloads for cross-boundary communication
  • federated identify
  • message routing
  • Health and activity tracking as well as monitoring across hybrid environments

From a vendor and solution perspective, I will highly recommend to pick a solution stack and technology provider that offers consistent design, development, deployment and monitoring tools across public, private and hybrid cloud environments.

Q: A customer comes to you today and says that they need to build an internal solution for exchanging data between a few custom and packaged software applications. If we assume they are a Microsoft-friendly shop, how do you begin to identify whether this solution calls for WCF/WF/AppFabric, BizTalk, ASP.NET Web API, or one of the many open source / 3rd party messaging frameworks?

A:  I think it depends a lot on the nature of the solution and 3rd party systems involved. Windows Server AppFabric are a great fit for solutions built using WCF/WF and ASP.NET technologies. BizTalk is a phenomenal technology for all things EAI with Adapters for SAP, Oracle, and Seibel etc. it’s a go to product for such scenarios. Honestly it depends on the situation. BizTalk is more geared towards EAI and ESB capabilities. WCF/WF and AppFabric are great at exposing LOB capabilities through web services. More often than not we see WCF/WF working side by side with BizTalk.

Q [stupid question]: The popular business networking site LinkedIn recently launched an “endorsements” feature which lets individuals endorse the particular skills of another individual. This makes it easy for someone to endorse me for something like “Windows Azure” or “Enterprise Integration.” However, it’s also possible to endorse people for skills that are NOT currently in their LinkedIn skills profile. So, someone could theoretically endorse me for things like “firm handshakes”, “COM+”, or “making scrambled eggs.” Which LinkedIn endorsements would you like, and not like, on your profile?

A: (This is totally new to me 🙂 ). I would like to explicitly opt-in and validate all the “endorsements” before they start appearing on my profile. [Editors Note: Because endorsements do not require validation, I propose that we all endorse Hammad for “.NET 1.0”]

Thanks to Hammad for taking some time to chat with me!

Author: Richard Seroter

Richard Seroter is Director of Developer Relations and Outbound Product Management at Google Cloud. He’s also an instructor at Pluralsight, a frequent public speaker, the author of multiple books on software design and development, and a former editor plus former 12-time Microsoft MVP for cloud. As Director of Developer Relations and Outbound Product Management, Richard leads an organization of Google Cloud developer advocates, engineers, platform builders, and outbound product managers that help customers find success in their cloud journey. Richard maintains a regularly updated blog on topics of architecture and solution design and can be found on Twitter as @rseroter.

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