F# Interview Questions for Developers

F# has gained popularity in recent years due to its unique combination of functional programming and object-oriented programming features, its concise and expressive syntax, and its integration with the .NET ecosystem.

F# was created by Don Syme at Microsoft Research in the early 2000s. It was initially designed as a .NET-compatible functional programming language with the goal of simplifying complex programming tasks and improving developer productivity. F# has since evolved into a general-purpose language and is now part of the .NET ecosystem.

https://learn.microsoft.com/en-us/dotnet/fsharp/

In order to evaluate the expertise of F# developers during programming interviews, we provide a collection of hands-on coding exercises and interview questions outlined below. Additionally, we have developed a range of suggested methods to ensure that your interview inquiries accurately measure the candidates’ F# capabilities.

F# example question

Help us design a parking lot app

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

Interview best practices for F# roles

During effective F# interviews, it’s important to consider various factors, such as the candidates’ experience levels and the specific engineering role they are applying for. To ensure your F# interview questions produce the best results, we recommend following these best practices while engaging with candidates:

• Develop technical questions that mirror real-life scenarios within your organization. This approach not only keeps the candidate engaged but also enables you to more precisely evaluate their fit for your team.
• Encourage a cooperative atmosphere by allowing candidates to ask questions throughout the interview.
• Because of F#’s strong relationship to the .NET framework, candidates should also have an understanding of common .NET libraries.

Moreover, it’s essential to adhere to standard interview practices when carrying out F# interviews. This includes adjusting question difficulty based on the candidate’s skill level, providing timely feedback on their application status, and enabling candidates to ask about the assessment or collaborate with you and your team.