These questions are used mostly to assess senior developers, but there is a reason for that: Xamarin is deprecated; fewer and fewer juniors will be available from now on.
This guide provides a curated set of technical and behavioral questions, along with sample answer tips, to help you evaluate Xamarin Developers candidates consistently and fairly.
A Xamarin developer uses Microsoft’s Xamarin framework (built on C#/.NET) to write and maintain a single code‑base that compiles into fully native iOS and Android apps. Day‑to‑day, they design mobile UIs, connect the app to back‑end APIs, integrate native device features (camera, GPS, push notifications), test and debug with Visual Studio/Xamarin tooling, and handle publishing to the App Store and Google Play.
Xamarin programming requires developers to have a specific skill set to build, maintain, and test mobile applications successfully. These are the top skills to look for in Xamarin developers:
Xamarin mobile development enables programmers to build applications in different operating systems because of C#. This is why one of the first skills to look for in Xamarin developers is their proficiency in the C# language.
You can also filter candidates with a strong background in .NET-specific methods such as C# classes, lambda expressions, Async/Await, etc. Xamarin cross-platform app development frameworks are based on the Model-View-ViewModel (MVVM), a software design pattern used to break programs and organize codes into modules to speed up development and make it more efficient.
Xamarin apps are created through Visual Studio, a Microsoft integrated development environment that helps developers create mobile applications and web services. Candidates should have in-depth knowledge and proficiency in developing, deploying, and debugging applications through Visual Studio.
One of the main purposes of building mobile applications with Xamarin is its code reusability. Around 80%-90% of the code in Xamarin is reusable. Xamarin.Android, Xamarin.iOS, and Xamarin.Mac can target your app to those different platforms while allowing the app to have the same back-end. Make sure your Xamarin developer knows how to reuse code on different platforms once the code is running on one platform.
Xamarin provides extensive support for APIs and third-party libraries. Make sure that candidates are proficient in working with APIs and know how to integrate them into apps.
Additional Xamarin developer skills you should consider include:
5. NET .MAUI
Xamarin was discontinued in May 2024. NET .MAUI is its successor, but such a project migration isn’t just a one-click migration. You need to do it manually or use the .NET Upgrade Assistant to move the whole project to the NET .MAUI framework. Therefore, if you plan to transport a Xamarin legacy system, you need NET .MAUI skills.
Here are the best interview questions to assess Xamarin understanding and knowledge.
This question ensures your candidate knows how to migrate your application from the deprecated Xamarin.Forms to .NET MAUI.
Answer: It is possible to port a Xamarin project to .NET MAUI, but it is not a one-click process. There are two main approaches:
Key steps in migration include:
Migration requires careful planning and involves updating the project structure, code, dependencies, and dealing with API differences.
This question discusses communication between multiple ViewModels.
Answer: Use some patterns like Prism’s Event Aggregator or message bus. EventAggregator provides multicast publish/subscribe functionality to the ViewModels, meaning that multiple publishers have the same event. MessageBus can also be employed to send messages between different layers of the code.
A Senior-level question, so you may evaluate experience from different projects.
Answers might include integrating iOS’s ARKit or Android’s NFC in a Xamarin.Forms app by creating service interfaces or custom renderers. Other example: writing a binding library for a native SDK, then using DependencyService to call it.) There are many other examples, so just see if it fits your project’s needs.
A mid-level developer might know the basics; this leans toward those advanced among them.
Answer: Xamarin.iOS uses AOT by default (no JIT on iOS) – discuss what that means for performance and app size. Xamarin.iOS, Ahead-of-Time (AOT) compilation is the default approach. It means your C# code is translated into native machine code before the application runs, instead of during runtime (Just-In-Time or JIT). This pre-compilation process results in faster application startup times and can also lead to a smaller app size. Have they ever encountered issues that required using the –llvm or other AOT settings to improve performance?
This is a good question for experienced developers in general, you just need to make some adjustments. The goal here is less about the tool and more about how they use it in a challenging environment.
For example: handling Apple’s 64-bit requirement (since 2015), Android target SDK version changes (and adapting to runtime permission changes or Google Play requirements), addressing app store rejections due to using restricted APIs… how your candidate dealt with such changes.
By asking this question you want to assess system-level thinking, time-boxing, and stakeholder communication.
This answer will surfaces conflict-resolution skills and data-driven persuasion.
You want to check coaching style and ability to elevate team capability.
Tests calm under pressure, root-cause analysis, and post-mortem best practices.
Evaluates judgment in aligning engineering quality with product priorities.
pprof or debugs a race‑detected test—real‑world tasks filter out copy‑paste coders.