Hiring guide for Elixir Binaries Engineers

Elixir Binaries Developer Hiring Guide

Elixir is a dynamic, functional language designed for building scalable and maintainable applications. It was created by José Valim in 2011 and runs on the Erlang virtual machine (BEAM), which is known for running low-latency, distributed, and fault-tolerant systems. Elixir leverages the Erlang VM's abilities to build concurrent, distributed, fault-tolerant applications with hot code upgrades. The language also provides productive tooling and an extensible design, supported by macros, for metaprogramming. Elixir's binaries are a way to handle large amounts of binary data efficiently, making it a popular choice for web development and embedded software.

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

First 20 minutes

General Elixir Binaries app knowledge and experience

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

What are the basic data types in Elixir?
The basic data types in Elixir are: integers, floats, booleans, atoms, strings, lists, and tuples.
How would you define a function in Elixir?
In Elixir, a function is defined using the 'def' keyword inside a module. For example: defmodule MyModule do def my_function do 'Hello, World!' end end.
What is pattern matching in Elixir?
Pattern matching in Elixir is a powerful feature that allows you to match simple as well as complex data structures, destructure data, and assign variables.
How would you handle errors in Elixir?
In Elixir, errors are handled using the try, catch, and rescue constructs. You can also use the 'with' keyword to handle errors in a more declarative way.
What are Elixir processes?
Elixir processes are lightweight threads of execution that are isolated and run concurrently. They are not OS processes or threads, but rather they are managed by the Erlang Virtual Machine (BEAM).
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What you’re looking for early on

Does the candidate have a strong understanding of Elixir Binaries?
How well does the candidate problem-solve under pressure?
Is there any experience of working in a team-based environment?
Can the candidate communicate technical information clearly?

Next 20 minutes

Specific Elixir Binaries 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.

Describe the difference between lists and tuples in Elixir.
In Elixir, lists are stored as linked lists, making it efficient to insert elements at the head of the list. Tuples, on the other hand, are stored contiguously in memory, making it efficient to access an element by index.
What is the role of the pipe operator in Elixir?
The pipe operator (|>) in Elixir is used to chain function calls together. It takes the output of one function and passes it as the first argument to the next function.
How would you work with binary data in Elixir?
In Elixir, binary data is represented as a sequence of bytes enclosed in <<>>. You can use pattern matching to destructure binary data, and the Bitwise module to manipulate bits.
What are Elixir protocols?
Protocols in Elixir are a way to achieve polymorphism. They allow you to define a function for multiple data types, and the correct implementation will be chosen at runtime based on the data type.
How would you implement a GenServer in Elixir?
A GenServer in Elixir is implemented by defining a module that uses the GenServer behaviour, and implementing the required callbacks, such as handle_call, handle_cast, and init.
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The ideal back-end app developer

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

At this point, a skilled Elixir Binaries engineer should demonstrate strong problem-solving abilities, proficiency in Elixir Binaries 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 Elixir Binaries.

What does this simple Elixir code do?
IO.puts "Hello, World!"
This code prints the string 'Hello, World!' to the console.
What does this Elixir code do?
defmodule Math do
  def add(a, b) do
    a + b
This code defines a module named 'Math' with a function 'add' that takes two parameters and returns their sum.
What will be the output of this Elixir code?
list = [1, 2, 3, 4, 5]
Enum.map(list, fn x -> x * 2 end)
This code will output a new list where each element is twice the corresponding element in the original list. So, the output will be [2, 4, 6, 8, 10].
What does this Elixir code do?
defmodule Worker do
  use GenServer

  def start_link do
    GenServer.start_link(__MODULE__, :ok, name: __MODULE__)
This code defines a GenServer (a server in the OTP framework) named 'Worker'. The 'start_link' function starts the server and links it to the current process.

Wrap-up questions

Final candidate for Elixir Binaries 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 Elixir Binaries application deployments. Inquire about their experience in handling system failures and their approach to debugging and troubleshooting.

What is the difference between Elixir and Erlang binaries?
Elixir binaries are essentially the same as Erlang binaries. However, Elixir provides additional syntactic sugar and helper functions to make working with binaries easier.
How would you handle state in an Elixir application?
State in an Elixir application is typically handled using processes. Each process has its own state, and you can send messages to a process to query or update its state.
What are Elixir macros and how would you use them?
Macros in Elixir are a way to define reusable chunks of code. They are a form of metaprogramming and can be used to generate code at compile time.

Elixir Binaries application related

Product Perfect's Elixir Binaries development capabilities

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