Product Perfect

Elixir Ports is a computer programming language designed for building scalable and maintainable applications. It was developed by José Valim in 2011, who aimed to create a language that enables higher extensibility and productivity. Elixir runs on the Erlang virtual machine (BEAM), which provides it with distributed and fault-tolerant capabilities, ideal for concurrent systems. The "Ports" refers to the mechanism used in Elixir for communicating with external programs running outside of its environment. This feature makes it versatile as it can interact seamlessly with other languages or system components.

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

First 20 minutes

General Elixir Ports app knowledge and experience

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

What is the purpose of Elixir Ports?

Elixir Ports provide a mechanism for the Elixir program to communicate with the external world, allowing it to interact with external programs written in other languages.

How would you create a new Port in Elixir?

You can create a new Port in Elixir using the Port.open function, passing in the command and the options as arguments.

What are the main options you can pass to the Port.open function?

The main options you can pass to the Port.open function are :in, :out, :binary, :exit_status, and :nouse_stdio.

How would you send data to a Port in Elixir?

You can send data to a Port in Elixir using the Port.command function, passing in the Port and the data as arguments.

What happens when a Port in Elixir receives data?

When a Port in Elixir receives data, it sends a message to the process that opened the Port. The message is a tuple containing the Port, the atom :data, and the received data.

The hiring guide has been successfully sent to your email address.

Oops! Something went wrong while submitting the form.

What you’re looking for early on

Does the candidate have a strong understanding of Elixir Ports?

Has the candidate demonstrated problem-solving skills?

Is the candidate able to communicate effectively?

Has the candidate shown a good understanding of OTP (Open Telecom Platform)?

Next 20 minutes

Specific Elixir Ports 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.

How would you close a Port in Elixir?

You can close a Port in Elixir using the Port.close function, passing in the Port as an argument.

What are the differences between Ports and Tasks in Elixir?

Ports and Tasks in Elixir are both used for concurrency, but they have different use cases. Ports are used for interacting with external programs, while Tasks are used for concurrent computation within the Elixir program.

How would you handle errors in a Port in Elixir?

You can handle errors in a Port in Elixir by receiving and pattern matching on the :EXIT message from the Port. The :EXIT message contains the Port and the reason for the exit.

What is the purpose of the :nouse_stdio option in the Port.open function?

The :nouse_stdio option in the Port.open function is used to indicate that the Port should not use the standard input and output of the Elixir program. This is useful when the external program does not interact with the Elixir program through standard input and output.

How would you read data from a Port in Elixir?

You can read data from a Port in Elixir by receiving and pattern matching on the :data message from the Port. The :data message contains the Port and the received data.

The hiring guide has been successfully sent to your email address.

Oops! Something went wrong while submitting the form.

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

What does this simple Elixir code do?
{:ok, file} = File.open('example.txt', [:write])
IO.binwrite(file, 'Hello, World!')
File.close(file)
This code opens a file named 'example.txt' in write mode, writes the string 'Hello, World!' to it, and then closes the file.
What will be the output of this Elixir code?
IO.puts(Enum.join(Enum.take(Enum.shuffle(Enum.to_list(1..10)), 5), ', '))
This code will output a comma-separated string of 5 random numbers between 1 and 10.
What does this Elixir code do?
list = [1, 2, 3, 4, 5]
Enum.map(list, fn x -> x * 2 end)
This code takes a list of numbers and returns a new list where each number is multiplied by 2.
What does this Elixir code do?
Task.async(fn -> heavy_computation() end)
|> Task.await()
This code runs a function named 'heavy_computation' asynchronously in a separate process and then waits for the result.

Wrap-up questions

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

What is the purpose of the :binary option in the Port.open function?

The :binary option in the Port.open function is used to indicate that the data sent to and received from the Port should be in binary format. This is useful when the external program communicates with the Elixir program using binary data.

How would you handle the exit status of a Port in Elixir?

You can handle the exit status of a Port in Elixir by receiving and pattern matching on the :EXIT_STATUS message from the Port. The :EXIT_STATUS message contains the Port and the exit status of the external program.

What are the differences between Ports and Sockets in Elixir?

Ports and Sockets in Elixir are both used for communication, but they have different use cases. Ports are used for communication with external programs, while Sockets are used for network communication.

Elixir Ports application related

Product Perfect's Elixir Ports development capabilities

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

Elixir Ports Consultive assessments

Elixir Ports Application Conversion Assessment Elixir Ports Application Integration Assessment Elixir Ports Data & Database Integration Assessment

Custom Elixir Ports development projects

Custom Elixir Ports App Conversion Elixir Ports Custom App Development Process App UI Design for Elixir Ports Facelifts

Hiring guide for Elixir Ports Engineers

Elixir Ports Developer Hiring Guide

What you’re looking for early on

The ideal back-end app developer

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

Elixir Ports Consultive assessments

Custom Elixir Ports development projects