Kotlin Interview Questions for Developers

Known primarily for its use in Android development — Google announced it as an official Android language in 2017 — Kotlin is also popular for its Java interoperability, concise syntax, and null safety type system.

According to the CoderPad 2023 Developer survey, Kotlin is the 10th most in-demand language among technical recruiters and hiring managers.

We have designed functional coding assignments and interview queries specifically aimed at assessing developers’ Kotlin expertise during coding interviews. Moreover, we have assembled a collection of recommended guidelines to guarantee that your interview questions effectively measure the candidates’ proficiency in Kotlin .

Kotlin 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 Kotlin roles

In order to conduct effective Kotlin interviews, it is crucial to take into account multiple aspects, such as the applicant’s background and the specific engineering position. To guarantee a productive interview experience, we suggest implementing the following best practices:

• Design technical questions that mirror real-life business situations within your organization. This method will efficiently engage the applicant and help in assessing their compatibility with your team.
• Foster a collaborative atmosphere by motivating candidates to pose questions during the interview.
• Knowledge of coroutines and asynchronous programming may be useful for building non-blocking programs.

Furthermore, compliance with proven interview procedures is critical when conducting Kotlin interviews. This includes tailoring the difficulty of the questions to align with the applicant’s abilities, promptly updating them on the status of their application, and offering them the chance to inquire about the evaluation process and cooperation with you and your team.