Hiring guide for Erlang R16B03 Engineers

Erlang R16B03 Developer Hiring Guide

Erlang R16B03 is a robust computer programming language, developed by Ericsson in 1986 for telecommunication systems and distributed applications. This high-level language is renowned for its real-time systems and hot swapping capabilities, where code can be changed without stopping the system. Today, it finds extensive use in e-commerce platforms, telecoms routing devices and instant messaging apps like WhatsApp. The Erlang Open Telecom Platform (OTP), a collection of middleware libraries in the Erlang runtime environment was introduced with this version to facilitate software development further. For more information on its evolution or usage specifics refer to "The Evolution of an Erlang Programmer" by Francesco Cesarini and Simon Thompson.

Ask the right questions secure the right Erlang R16B03 talent among an increasingly shrinking pool of talent.

First 20 minutes

General Erlang R16B03 app knowledge and experience

The first 20 minutes of the interview should seek to understand the candidate's general background in Erlang R16B03 application development, including their experience with various programming languages, databases, and their approach to designing scalable and maintainable systems.

What is the primary use of Erlang?
Erlang is primarily used for building massively scalable soft real-time systems with requirements on high availability. It's used in telecoms, banking, e-commerce, computer telephony and instant messaging.
How would you define a function in Erlang?
In Erlang, a function is defined using the keyword 'fun'. The syntax is 'fun(Parameters) -> Body end'. The parameters are pattern matched, and the body contains the logic of the function.
What are the key features of Erlang?
Erlang has several key features including concurrency, distribution, fault tolerance, hot swapping, and support for real-time systems.
Describe the difference between lists and tuples in Erlang.
In Erlang, lists are used when the number of elements is variable, while tuples are used when the number of elements is fixed. Lists are enclosed in square brackets, while tuples are enclosed in curly brackets.
How would you handle errors in Erlang?
Erlang uses a 'let it crash' philosophy for error handling. Instead of trying to catch every possible error, Erlang encourages you to write code that does the right thing in the normal case, and crashes in the abnormal case.
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 the Erlang R16B03 language?
Is the candidate able to solve complex problems using Erlang R16B03?
How familiar is the candidate with the OTP framework?
Does the candidate demonstrate good communication skills?

Next 20 minutes

Specific Erlang R16B03 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 is the role of the Erlang VM (BEAM)?
The Erlang VM, also known as BEAM, is responsible for executing Erlang code. It provides features such as garbage collection, process scheduling, and I/O handling.
What are the different types of data types available in Erlang?
Erlang supports several data types including numbers, atoms, tuples, lists, maps, and binaries.
Describe the difference between spawn and spawn_link in Erlang.
Both spawn and spawn_link are used to create a new process in Erlang. The difference is that spawn_link links the new process to the current process, so if either process terminates, the other process will also be terminated.
How would you implement concurrency in Erlang?
Concurrency in Erlang is implemented using processes. Processes are lightweight, isolated entities that communicate with each other using message passing.
What is hot code swapping in Erlang?
Hot code swapping is a feature of Erlang that allows you to change the code of a running system without stopping or restarting the system. This is particularly useful for systems that require high availability.
The hiring guide has been successfully sent to your email address.
Oops! Something went wrong while submitting the form.

The ideal back-end app developer

What you’re looking to see on the Erlang R16B03 engineer at this point.

At this point, a skilled Erlang R16B03 engineer should demonstrate strong problem-solving abilities, proficiency in Erlang R16B03 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 Erlang R16B03.

What does this simple Erlang code do?
start() -> io:fwrite('Hello, World!\n').
This code defines a module named 'hello' and exports a function named 'start' with zero arguments. The 'start' function prints 'Hello, World!' to the console.
What will be the output of this Erlang code?
start() -> io:fwrite('~p~n', [lists:reverse([1,2,3,4,5])]).
This code will output the list [5,4,3,2,1]. The 'lists:reverse' function is used to reverse the order of the elements in the list [1,2,3,4,5].
What does this Erlang code do?
start() -> lists:map(fun(X) -> X*X end, [1,2,3,4,5]).
This code applies the anonymous function 'fun(X) -> X*X end' to each element in the list [1,2,3,4,5]. The result is a new list where each element is the square of the corresponding element in the original list.
What does this Erlang code do?
start(N) -> spawn(fun() -> do_something(N) end).
do_something(N) -> io:fwrite('Doing something with ~p~n', [N]).
This code spawns a new process that executes the function 'do_something' with the argument 'N'. The 'do_something' function prints a message to the console indicating that it is doing something with 'N'.

Wrap-up questions

Final candidate for Erlang R16B03 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 Erlang R16B03 application deployments. Inquire about their experience in handling system failures and their approach to debugging and troubleshooting.

What are the different ways to handle exceptions in Erlang?
Erlang provides several ways to handle exceptions, including try-catch expressions, error handling functions, and process linking and monitoring.
How would you implement a distributed system in Erlang?
Erlang provides built-in support for distributed systems. You can create a distributed system by running multiple Erlang nodes on different machines, and using message passing for communication between nodes.
What is the role of OTP in Erlang?
OTP (Open Telecom Platform) is a set of libraries and design principles for building robust, scalable, and maintainable Erlang applications. It provides features such as supervision trees, generic servers, and application packaging.

Erlang R16B03 application related

Product Perfect's Erlang R16B03 development capabilities

Beyond hiring for your Erlang R16B03 engineering team, you may be in the market for additional help. Product Perfect provides seasoned expertise in Erlang R16B03 projects, and can engage in multiple capacities.