Prepare for your Senior iOS Engineer interview. Understand the required skills and qualifications, anticipate the questions you may be asked, and study well-prepared answers using our sample responses.
This question can help the interviewer understand how you interact with your colleagues and whether you’re comfortable working on a team. Your answer should show that you enjoy working with others, but also that you have the ability to lead a team of developers if needed.
Answer Example: "Absolutely. I have extensive experience working with teams of developers to create new products. In my previous role, I was responsible for leading a team of five developers who worked together to create an iOS app for a large company. We used agile development methods to ensure that we were meeting deadlines while also providing high-quality work."
This question can help the interviewer determine if you have the skills necessary to succeed in this role. Use your answer to highlight some of the most important skills for an iOS engineer and explain why they are so important.
Answer Example: "As a Senior iOS Engineer, I believe the most important skills to have are excellent problem-solving abilities, strong communication skills, and an in-depth understanding of Apple’s iOS platform. Problem-solving is essential for troubleshooting issues with existing applications and developing new features. Strong communication skills are needed to collaborate with other engineers, designers, and stakeholders to ensure that projects are completed on time and within budget. Finally, an in-depth understanding of the iOS platform allows me to effectively design, develop, and test applications."
Debugging is a skill that all engineers need to have. The interviewer may ask this question to see how you approach problem-solving and whether your approach aligns with the company’s. In your answer, explain the steps you take when debugging an app and why those steps are important.
Answer Example: "When debugging a problem with an app, I like to start by taking a step back and looking at the big picture. This helps me understand what’s going on in the app as a whole and gives me an idea of where to start looking for the issue. Next, I’ll look at the code itself to see if there are any obvious issues that could be causing the problem. If not, I’ll start testing different parts of the app to see if any changes occur. Finally, if all else fails, I’ll reach out to my team members for help."
This question is a great way to test your knowledge of thread management in iOS. The answer to this question should include an explanation of what each term means, as well as an example of how you would use them in your work as an engineer.
Answer Example: "WCS stands for “Wait-Conditional Synchronization” and GCS stands for “Global-Conditional Synchronization.” WCS is used for thread management within a single thread, while GCS is used for managing multiple threads."
Concurrency is the ability to perform multiple tasks at once. This question is an opportunity to show your ability to work effectively with other engineers and manage multiple projects at once. When answering this question, it can be helpful to describe a specific situation where you used concurrency in your work and how it helped you achieve your goals.
Answer Example: "In my last role, I was responsible for developing an iOS app that allowed users to search for local businesses based on their location. The app needed to be able to process multiple searches at once, so I implemented concurrency to ensure that users could search for businesses without any lag time. By using concurrency, I was able to ensure that the app was able to handle multiple searches at once without affecting its performance."
This question is a great way for the interviewer to get an idea of your experience level and how you present yourself professionally. When answering this question, it can be helpful to mention some specific apps that you have worked on in the past and why they are relevant to the position you are interviewing for.
Answer Example: "I have extensive experience working on both consumer and enterprise apps. In my portfolio, you would see examples of both types of projects I’ve worked on. For consumer apps, I would expect to see an app similar to Uber or Lyft, as well as a gaming app like Candy Crush or Angry Birds. For enterprise apps, I would expect to see examples of apps that help businesses manage their operations more efficiently."
This question can help the interviewer determine how you approach new challenges. Use examples from past projects where you had to learn a new programming language or framework, and explain how you overcame any challenges associated with learning a new skill.
Answer Example: "If I were assigned to a project that required me to learn a new programming language, I would take it as an opportunity to expand my knowledge and develop my skills. First, I would research the language and learn as much as I can about its features and capabilities. Then, I would apply what I’ve learned to my work by writing code in the new language. Finally, I would review my code carefully to ensure that it is error-free. By taking this approach, I am able to quickly become proficient in using new languages and frameworks."
The interviewer may ask this question to assess your knowledge of the iOS SDK. The SDK is a collection of tools and libraries that help developers create apps for Apple’s operating system. Your answer should show that you have a strong understanding of the SDK and how it works.
Answer Example: "I have extensive experience working with the iOS SDK. I have developed several successful apps using the latest versions of Xcode, Swift, and Objective-C. I understand the ins and outs of the SDK, including how to use its various frameworks and libraries. I also know how to troubleshoot any issues that may arise during development."
This question can help the interviewer determine your level of experience with Xcode, Apple’s primary development tool. If you have previous experience working with Xcode, share what types of projects you’ve worked on and what you like most about the software. If you don’t have any experience working with Xcode, consider mentioning another development tool that you’re familiar with and how it compares to Xcode.
Answer Example: "Yes, I have extensive experience working with Xcode. I have been developing for iOS for over 5 years now, and have used Xcode throughout my career. During my time as a Senior iOS Engineer, I have been responsible for managing entire projects from start to finish, including creating prototypes, designing user interfaces, coding, testing, and debugging."
Delegates are a common concept in Objective-C programming. This question tests your knowledge of when it’s appropriate to use delegates in Objective-C and how they work. Your answer should include an example of when you’ve used delegates in the past and what the outcome was.
Answer Example: "Delegates are an excellent way to create a connection between two different objects in Objective-C. They allow one object to send messages to another object without having to know its class or type. This is useful when I need to call different methods on different objects without knowing what type of object they are. For example, I once created a game where the player could collect different types of items. Each item had its own method that could be called when the player collected it. To do this, I used delegates so that each item could send a message to the player without knowing what type of object it was."
This question is a great way to show your problem-solving skills and how you can improve the performance of an app. When answering this question, it’s important to explain the steps you would take to improve the app’s performance.
Answer Example: "I would first check if there are any bugs in the code that are causing the app to slow down. If not, I would look at the design of the app to see if there are any ways I can optimize it. For example, I could use fewer images or reduce the size of the files being used. I could also look into using caching techniques to store data locally so that it doesn’t have to be downloaded every time the app is used. Finally, I would make sure that all third-party libraries are up-to-date and compatible with the current version of iOS."
This question is a great way to test your knowledge of iOS development. Zero-based indexing is a method of organizing data in an array where the first element is 0, not 1. This method is common in iOS development, so it’s important to be able to explain your experience with it.
Answer Example: "I have extensive experience with zero-based indexing. I’ve used it in many of my projects, including my most recent project where I developed an app that used zero-based indexing for all of its data storage. The app was designed to be user-friendly, so I made sure to use zero-based indexing to ensure that all data was organized properly."
This question can help the interviewer determine your knowledge of the Objective-C language. Your answer should include an explanation of what makes Objective-C a dynamic language, including its ability to interact with other languages like C and Swift.
Answer Example: "Objective-C is a dynamic language because it allows me to interact with other languages such as C and Swift. This is done through something called ‘framework’, which is essentially a collection of code that allows me to use different languages within one project. For example, I can write some parts of my app in Swift while using other parts of the app in Objective-C. This makes it easier for me to work on projects that require multiple languages."
This question can help the interviewer understand your experience level and how you’ve adapted to different operating systems. If you have experience working with multiple operating systems, share that information with the interviewer. If you’ve only worked with one operating system, explain why you prefer it over others.
Answer Example: "I’ve worked with both Windows and Mac operating systems in the past. I find that Mac is easier to use because it has fewer complications when it comes to coding. Windows, on the other hand, is more versatile because it can be used for both desktop and mobile applications."
This question can help the interviewer get to know you as a person and how you approach challenges. Your answer can also show the interviewer that you are aware of what it takes to be successful in this role, which can be important for employers who are looking for someone with experience in the field.
Answer Example: "The most challenging part of being an iOS engineer is staying up to date with the ever-changing technology. As technology advances, so do the requirements for iOS engineers. It’s important to be able to adapt to these changes in order to create the best possible products for users."
This question can help the interviewer determine how committed you are to your career and whether you’re likely to stay with their company for a long time. Your answer should show that you have an interest in learning new things, but it’s also important to mention any certifications or training you’ve completed recently.
Answer Example: "I am always looking for ways to improve my programming skills. I regularly attend webinars and online courses about different coding languages and technology trends. In fact, I just finished a course on Swift 4 development last month. I also make sure to read up on the latest news in the tech industry so that I can stay up-to-date on what’s happening in the world of technology."
This question can help the interviewer understand how you approach challenges in your work. Your answer should show that you are willing to take responsibility for your actions and are willing to fix problems that arise.
Answer Example: "When I encounter a bug in an app I’ve been working on, my first step is to determine what caused it. This involves carefully reviewing my code and looking for any inconsistencies or errors. Once I have identified the source of the issue, I will then work on fixing it."
