Hiring guide for Fantom Engineers

Fantom Developer Hiring Guide

Fantom is a general-purpose, object-oriented programming language that was initially released in 2005 by Brian and Andy Frank. It was designed to be portable across various platforms including Java Virtual Machine (JVM) and JavaScript interpreters. The Fantom ecosystem includes a standard library, a build system, testing framework, and documentation toolset. Its syntax is similar to C#, Java or Kotlin with added features for concurrency management inspired from Erlang's actor model. Despite its versatility and robustness as an efficient cross-platform development tool, it remains relatively obscure within the broader software development community.

Ask the right questions secure the right Fantom talent among an increasingly shrinking pool of talent.

First 20 minutes

General Fantom app knowledge and experience

The first 20 minutes of the interview should seek to understand the candidate's general background in Fantom application development, including their experience with various programming languages, databases, and their approach to designing scalable and maintainable systems.

How would you define Fantom?
Fantom is a general-purpose, object-oriented, portable programming language that runs on the Java Runtime Environment (JRE), JavaScript, and .NET Common Language Runtime (CLR). It is designed to be easy to use, with a familiar syntax for Java and C# developers.
What are the key features of Fantom?
Fantom has several key features including: static and dynamic typing, functional programming, concurrency programming, and a standard library that includes a cross-platform API for file I/O, serialization, reflection, and more.
How would you create a class in Fantom?
In Fantom, you would create a class using the 'class' keyword followed by the class name. For example, 'class MyClass { }'.
What is the role of the 'using' statement in Fantom?
The 'using' statement in Fantom is used to import a namespace or a type into the current scope. It is similar to the 'import' statement in Java.
How would you handle exceptions in Fantom?
In Fantom, exceptions are handled using 'try-catch' blocks. You can also use the 'throw' statement to throw an exception.
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What you’re looking for early on

Does the candidate have a solid understanding of Fantom?
Has the candidate demonstrated problem-solving skills?
Is the candidate familiar with the tools commonly used in Fantom development?
Can the candidate communicate effectively about technical concepts?

Next 20 minutes

Specific Fantom development questions

The next 20 minutes of the interview should focus on the candidate's expertise with specific backend frameworks, their understanding of RESTful APIs, and their experience in handling data storage and retrieval efficiently.

What are mixins in Fantom?
Mixins in Fantom are a type of inheritance that allows you to include behavior from multiple sources in a class. They are similar to interfaces in Java, but they can also include implementation code.
How would you implement concurrency in Fantom?
In Fantom, concurrency is implemented using the 'Actor' model. You can create an actor by extending the 'Actor' class and overriding the 'receive' method.
Describe the difference between static and dynamic typing in Fantom.
In Fantom, static typing means that the type of a variable is known at compile time, while dynamic typing means that the type of a variable is known at runtime. Fantom supports both static and dynamic typing.
What is the purpose of the 'sys' pod in Fantom?
The 'sys' pod in Fantom provides core functionality and types that are used by all other pods. It includes basic types like Int, Str, Bool, and more.
How would you create a singleton in Fantom?
In Fantom, you can create a singleton using the 'singleton' keyword. For example, 'singleton class MySingleton { }'.
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The ideal back-end app developer

What you’re looking to see on the Fantom engineer at this point.

At this point, a skilled Fantom engineer should demonstrate strong problem-solving abilities, proficiency in Fantom programming language, and knowledge of software development methodologies. Red flags include lack of hands-on experience, inability to articulate complex concepts, or unfamiliarity with standard coding practices.

Digging deeper

Code questions

These will help you see the candidate's real-world development capabilities with Fantom.

What does this simple Fantom code do?
class Hello {
  static Void main() {
    echo("Hello, World!")
This code defines a class named 'Hello' with a static method 'main'. When this program is run, it will print 'Hello, World!' to the standard output.
What does the following Fantom code do?
class Test {
  Int add(Int a, Int b) {
    return a + b
This code defines a class named 'Test' with a method 'add'. This method takes two integer parameters, adds them together, and returns the result.
What will be the output of the following Fantom code?
class Main {
  static Void main() {
    list := [1, 2, 3, 4, 5]
    list.each |Int num| { echo(num * 2) }
This code will print the doubled value of each number in the list. So the output will be '2', '4', '6', '8', '10' each on a new line.
What does the following Fantom code do?
class Main {
  static Void main() {
    Actor { echo("Hello, World!") }.send
This code starts an ActorPool and sends a message to a new Actor. The Actor's behavior is to print 'Hello, World!' to the standard output. This demonstrates basic usage of Fantom's concurrency model.

Wrap-up questions

Final candidate for Fantom Developer role questions

The final few questions should evaluate the candidate's teamwork, communication, and problem-solving skills. Additionally, assess their knowledge of microservices architecture, serverless computing, and how they handle Fantom application deployments. Inquire about their experience in handling system failures and their approach to debugging and troubleshooting.

What are closures in Fantom and how would you use them?
Closures in Fantom are anonymous functions that can capture variables from their surrounding scope. You can use them as arguments to higher-order functions, or to create function-like objects.
Describe the difference between 'const' and 'val' in Fantom.
In Fantom, 'const' is used to declare a constant, whose value cannot be changed once it is assigned. 'val', on the other hand, is used to declare a read-only field, whose value can be assigned once, but cannot be changed afterwards.
How would you implement polymorphism in Fantom?
In Fantom, polymorphism is implemented through inheritance and interfaces. A class can inherit from another class or implement an interface, and then override the methods defined in the superclass or interface.

Fantom application related

Product Perfect's Fantom development capabilities

Beyond hiring for your Fantom engineering team, you may be in the market for additional help. Product Perfect provides seasoned expertise in Fantom projects, and can engage in multiple capacities.