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Code tests for iOS Developers

This article provides practical suggestions for your iOS test code assignments. Here, we offer a set of thoughtful iOS assignments designed not just to test the technical knowledge of iOS developers but also to inspire creativity and innovation in their approach to problem-solving.

What to look for in an iOS developer

When identifying an exceptional iOS developer, the focus should be on a harmonious blend of technical expertise and a deep understanding of the iOS platform. A standout developer is fluent in Swift and SwiftUI and adept at creating functional, aesthetically pleasing, and intuitive user interfaces. Their skill in Swift is complemented by an in-depth knowledge of data management, particularly with Core Data, ensuring efficient and secure handling of data.

Moreover, such a developer is technically proficient and creatively versatile. They demonstrate a keen adherence to Apple's Human Interface Guidelines, ensuring that the apps they develop resonate with the platform's design ethos and provide a seamless user experience.

Their technical understanding extends to integrating applications within the broader Apple ecosystem, leveraging technologies like HealthKit, HomeKit, and WatchKit. This integration underscores their understanding of creating a unified user experience across various Apple devices.

Understanding the App Store's role is crucial in iOS app development. It's important to navigate its submission and review its process effectively, ensuring compliance with Apple's guidelines. App Store Optimization (ASO) is key for enhancing app visibility and attractiveness. Post-launch, developers should focus on regular updates, responding to user feedback, and adapting to evolving guidelines. This knowledge is vital for successfully deploying and maintaining an app in the competitive App Store environment.

What should the candidate deliver?

The candidate's mastery of Xcode and the iOS development environment is crucial. They should demonstrate deep familiarity with Xcode's interface, debugging tools, and performance profiling capabilities. Their skill set must also encompass other essential iOS tools and libraries, showcasing a comprehensive understanding of the platform.

Code quality is paramount. Submissions should reflect well-documented, clean, and maintainable Swift code, conforming to Apple's coding standards. This reflects their technical proficiency and approach to code quality. Whether their chosen programming language is Swift or Objective-C, they should be capable of arguing their choices.

The design and user experience of the app must adhere to Apple's Human Interface Guidelines, highlighting the developer's ability to create intuitive and visually appealing user interfaces for various iOS devices. If relevant, the app should integrate seamlessly with essential iOS services, demonstrating the developer's capability to utilize the full potential of the iOS ecosystem.

Finally, comprehensive unit and UI tests are essential, evidencing the developer's commitment to quality assurance and proficiency in using Xcode's testing frameworks. This ensures the delivery of a robust and reliable iOS application.

Five suggestions for iOS code assessment tasks

When assigning code tests to potential iOS developer candidates, it's worth noting that many reputable companies often provide their backend systems. While open-source APIs exist, they reflect poorly on the organization when they hand out code assignments without doing any work themselves.

The projects listed below are designed to evaluate a broad spectrum of skills for developing apps, from UI/UX design to advanced system integrations. These project ideas challenge the developer's technical capabilities and ability to integrate with existing systems. The code challenges should be at most a day or two of work.

1. Habit tracker application

This project evaluates skills in local data persistence on iOS. The app should allow users to track daily habits, set goals, and monitor progress, leveraging Core Data or similar frameworks for local storage. It will test the developer's ability to manage and store data efficiently on-device.

2. Social media application

This project tests the candidate's ability to manage real-time data, user interactions, and multimedia content. The app should feature a feed, messaging capabilities, and media sharing. It will evaluate the developer's skills in creating dynamic and responsive interfaces, handling asynchronous data, and integrating multimedia elements.

3. Health/fitness application

This app focuses on integrating with HealthKit and using motion sensors and GPS. The candidate should showcase their ability to work with Apple SDKs and device hardware. Features might include activity tracking, health metrics monitoring, and personalized fitness recommendations, demonstrating proficiency in handling health-related data and sensor integration.

4. Augmented reality (AR) application

Using ARKit, this project assesses the developer's understanding of AR technologies. The app could involve interactive AR experiences, like virtual try-ons or immersive games, testing the candidate's skills in creating engaging AR content and their grasp of spatial computing concepts.

5. Internet-of-Things (IoT) application

This app should demonstrate integration with the Apple ecosystem and IoT devices, possibly through HomeKit. It could control smart home devices or collect data from IoT sensors. This project tests the developer's abilities in networking, device integration, and working within the Apple ecosystem.

Additional topics of conversation

iOS development is an evolving field, both due to Apple’s innovation as well as the user base that traditionally demands higher-end experience. Oftentimes the job of developers is to compete with applications developed by multinational companies, who can invest time, research, and resources into developing the best possible experience. Luckily, iOS developers have access to incredible documentation and a plethora of examples to learn from.

Security and privacy-focused development

In the current digital landscape, security and privacy are paramount in iOS app development. It is no longer enough that developers excel in software development alone; nowadays, they must be well-versed in encrypting sensitive data, securing network connections, and safeguarding user privacy.

Understanding the iOS operating system, and implementing Apple’s security guidelines and best practices, such as using HTTPS, securing data using Keychain, and handling permissions responsibly, is essential. Additionally, staying up-to-date on the latest security threats and mitigation strategies is crucial.

Privacy concerns extend to how user data is collected, used, and shared, requiring developers to be knowledgeable about privacy laws and regulations, such as GDPR, and incorporating transparent privacy policies within their apps.

Accessibility and internationalization

In iOS app development, accessibility is not just a feature but a fundamental aspect that ensures apps are usable by everyone, including individuals with disabilities. A proficient iOS developer must understand and implement Apple's accessibility features, such as VoiceOver, dynamic type, and assistive touch. This involves designing user interfaces that are navigable and readable for users with vision impairments, incorporating auditory cues for those with hearing difficulties, and ensuring that app controls are accessible to users with motor impairments. Beyond technical implementation, developers should also have an awareness of the diverse ways users interact with technology, creating inclusive and adaptable user experiences.

Internationalization in iOS apps goes beyond simple translation of text. It encompasses adapting the app’s content and functionality for different languages, regions, and cultures. This requires developers to architect apps in a way that makes it easy to switch languages and formats. It involves not only translating text but also adapting layouts to accommodate different text directions and lengths and ensuring cultural appropriateness in icons, images, and color choices. Developers must also consider local regulations and preferences, which can influence the app's functionality and acceptance in different markets.

Understanding SwiftUI and UIKit

A comprehensive understanding of both SwiftUI and UIKit is vital for modern iOS developers. SwiftUI, Apple’s latest UI toolkit, offers a declarative syntax and a more straightforward way to build interfaces across all Apple platforms. It allows for quicker development and easier maintenance but is limited in terms of backward compatibility and customization. UIKit, on the other hand, provides a more established and detailed control of UI elements, making it suitable for complex applications that require granular control. An adept iOS developer should be able to assess the project requirements, user base, and desired app features to decide whether to use SwiftUI, UIKit, or a combination of both for the best outcome.


This article provides a comprehensive guide for assessing iOS candidates, emphasizing areas such as proficiency in Swift and SwiftUI, integration with various iOS services, and a general understanding of the Apple ecosystem.

It underscores the importance of accessibility, internationalization, security, and privacy. Additionally, it highlights the critical role of understanding the nuances of the App Store. This serves as the right blend of technical skills and platform-specific knowledge, ensuring the development of high-quality, user-centric iOS applications.

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