Swift Interview Questions for Developers

The preferred language for macOS/iOS applications, Swift is also popular for its readability & simplicity, its fast and efficient performance, and its strong corporate backing by Apple.

In December 2015, Apple open-sourced Swift under the Apache License 2.0, allowing the broader developer community to contribute to its development and improvement. The Swift project is now available on GitHub, with ongoing enhancements and updates driven by both Apple and the community.

https://swift.org/blog/swift-is-now-open-source/

Our team has developed practical programming assignments and conversation prompts, tailored to measure the Swift proficiency of developers during coding assessments. Furthermore, we have compiled a set of best practices to ensure the accuracy of your interview questions in evaluating candidates’ skills in Swift.

Swift example question

Help us design a parking lot

Hey candidate! Welcome to your interview. Boilerplate is provided. Feel free to change the code as you see fit. To run the code at any time, please hit the run button located in the top left corner.

Goals: Design a parking lot using object-oriented principles

Here are a few methods that you should be able to run:

• Tell us how many spots are remaining
• Tell us how many total spots are in the parking lot
• Tell us when the parking lot is full
• Tell us when the parking lot is empty
• Tell us when certain spots are full e.g. when all motorcycle spots are taken
• Tell us how many spots vans are taking up

Assumptions:

• The parking lot can hold motorcycles, cars and vans
• The parking lot has motorcycle spots, car spots and large spots
• A motorcycle can park in any spot
• A car can park in a single compact spot, or a regular spot
• A van can park, but it will take up 3 regular spots
• These are just a few assumptions. Feel free to ask your interviewer about more assumptions as needed

Best interview practices for Swift roles

To ensure successful Swift interviews, it’s important to consider various factors, such as the candidate’s background and the specific engineering role. To create a positive interview experience, we recommend adopting the following best practices:

• Formulate technical questions that reflect real-world business scenarios within your organization. This approach will effectively engage the candidate and help in assessing their compatibility with your team.
• Foster a collaborative environment by inviting candidates to ask questions throughout the interview.
• Ensure candidates possess knowledge of Auto Layout and constraints for creating responsive apps.

Additionally, it’s important to follow standard interview practices when conducting Swift interviews. This involves adjusting question difficulty based on the candidate’s abilities, providing prompt updates about their application status, and allowing them to inquire about the assessment process and collaboration with you and your team.