This most efficient business solution to manage risk is a Minimum Viable Product (MVP). At Salty Dog Technology we create MVP’s to test the basic functionality needed to verify solutions.

Having a MVP that includes a back-end amplifies risk beyond a stand-alone architecture. These risks fall into three common categories: cost, time and flexibility.

Cost matters.  An MVP’s costs can spiral if the back-end implementation is expensive operate or takes a lot of hours to build. Though not in plain sight, the server’s cost should not be underestimated.

Time matters.  If you go the route of building everything from scratch, it can take longer, be more error prone and require more testing. There is a lot of “plumbing” that needs to be implemented in that case.  You can miss product release goals if this is not taken into account when making development schedules.

Flexibility matters.  Building a back-end from scratch requires finding or creating a bunch of scaffolding functionality. If you use a 3rd party framework, then you bring its baggage along, which may be more trouble than it’s worth. All frameworks are built with assumptions that may, or may not be ideal for your app’s back-end. A back-end implementation that cannot easily change will incur higher costs and take more time.

There are some 3rd party back-end services you can try such as Facebook’s defunct and now open-sourced Parse Server, or Google’s Firebase. They have a vested interest in locking you into their service and libraries, and often they have tiered pricing which may not reflect your usage. This means that you may end up having to pay a lot more and have less ability to change.


A Middle Solution


At Salty Dog, we use a strategy that combines three Microsoft programs: Azure Functions, Azure DocumentDB and Xamarin.

Azure Functions:  Azure  Functions are a way of providing server functionality without actually having to create a server. You are charged for the resources when they are used, as opposed to a virtual machine which incurs ongoing costs independent of actual usage.

Azure functions are not tied to single computational resources. The more that your Azure functions are accessed, the more computational resources will be automatically applied. This allows the Azure functions smoothly scale according to application needs.

Azure functions provide a rich programming environment where the functionality can be implemented in a number of languages including C #, PHP, JavaScript, Python and others.  They can utilize third-party libraries to provide extra functionality, as well as access external resources such as databases and messaging infrastructures.

DocumentDB:   DocumentDB is a server-less, schema-less JSON document database. Document DB stores the data in hierarchical JSON documents. They are indexable by primary and secondary keys. Like Azure Functions, it scales smoothly as your needs grow.

This means that time doesn’t have to be spent creating the schema, updating the schema, making sure that all data passed conforms to the structure. All of those things take time. Purists would argue that those up-front definitions provide a higher level of quality, and they’re right. However, that purity and build-in checking comes at a cost that isn’t necessary with an MVP.

Azure provides is an SQL interface to DocumentDB that understands some aspects of JavaScript syntax. This gives you a known query language that can leverage Javascript data aspects.

Xamarin:  Xamarin provides a set of tools to build Android, iOS, and Mac OS apps using C#. Rather than writing in Java, Objective-C or Swift, you write in C#. It is compatible with a lot of existing .Net libraries that can be used directly in the applications.

There are multiple ways to use similar functionality across the platforms in a generic way. Typically this is done using an IoC or Inversion of Control, system.  This means that someone can create a GPS widget that is used the same way, down to the API level, on both Android or iOS.  Below the surface, it accesses the specific native functionality on the device. This means the code you write doesn’t have to know if it is running on Android or iOS.

Xamarin has created a cross platform user interface library called Xamarin Forms. Xamarin Forms provides a usable lowest common denominator UI with the ability to customize and enhance it. For less fancy or performance sensitive applications, such as games, it can speed up development.


The Right Building Blocks


Together, the three tools provide a solution to the main risks we identified.

Cost is saved.  Infrastructure, routing, and boilerplate are built in. A lot of the “plumbing” is in place.  Azure Functions feels like you’re working with a bigger web framework, without sacrificing flexibility.

Pricing is relative to the actual time a particular function is performing work. If one month the Azure Function is only used for an hour demo, we will only be charged for that hour. Conversely, if the month after that, we put our app in the hands of 50 potential clients and they use it heavily, the infrastructure will smoothly scale to meet their demand without any intervention on our part.

Using Xamarin for mobile development, especially Xamarin Forms, enables code reuse, since the same piece of code may be able to run on either Android or iOS. Development will not be done twice as it would have been if building native apps.

Time is saved. Apps can be developed locally, unit tested, and put on the server using common source control methods, like Git and branching.  It isn’t necessary to continually upload to the servers and test. This makes it easy to add features, find bugs and fix them. When the code is ready changes are pushed to the right branch, and then Azure Functions will execute a pull from the control panel. This allows multiple live versions that correspond to production phases such as “beta” and “development,” or whatever makes sense for our product. With Xamarin, the app can be separated into distinct parts  for testing in isolation outside of a mobile device.  This can save time in the develop, test, and fix cycle.

Flexibility is saved.  Since the interface between the application and the web server is the well-known REST standard, your app isn’t locked in because of special libraries.




Creating MVP’s for mobile need not be time consuming or require huge infrastructure investments.  Using Azure Functions, Azure DocumentDB, and Xamarin allows code to be quickly developed, unit tested, and reused. Used in conjunction, they allow you to focus on the MVP and its refinement without worrying as much about cost, development time, and flexibility.