Erlang R16B03-1 Developer Hiring Guide

Hiring Guide for Erlang R16B03-1 Engineers

Ask the right questions to secure the right Erlang R16B03-1 talent among an increasingly shrinking pool of talent.

Erlang R16B03-1 is a robust computer programming language, developed by Ericsson in the 1980s for telecommunication systems. It was designed to handle large-scale concurrent activities, making it ideal for real-time systems and distributed computing applications. The language is known for its fault-tolerance and hot-swapping capabilities, which allow code updates without stopping the system. Erlang's syntax is inspired by Prolog and it supports functional programming with dynamic typing. This information can be referenced from "Programming Erlang: Software for a Concurrent World" by Joe Armstrong, one of the original creators of Erlang at Ericsson.

First 20 minutes

General Erlang R16B03-1 knowledge and experience

The next 20 minutes of the interview should attempt to focus more specifically on the development questions used, and the level of depth and skill the engineer possesses.

How would you implement a recursive function in Erlang?

A recursive function in Erlang can be implemented by defining a function that calls itself. The function must also have a base case to prevent infinite recursion.

Describe the difference between lists and tuples in Erlang.

In Erlang, lists are used when the number of elements can vary, while tuples are used when the number of elements is fixed. Lists are also used when elements need to be added or removed, while tuples are used when elements are just read.

What are the advantages of using Erlang for concurrent programming?

Erlang provides lightweight processes, message passing concurrency, and built-in support for distribution. These features make it a good choice for concurrent programming.

How would you handle errors in Erlang?

In Erlang, errors are handled using the 'let it crash' philosophy. This means that when an error occurs, the process that encountered the error is allowed to crash and a supervisor process then decides what action to take.

What is the use of the spawn function in Erlang?

The spawn function in Erlang is used to create a new process. It takes a function as an argument and runs it in a separate process.

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What youre looking for early-on

Does the candidate have a good understanding of OTP (Open Telecom Platform)?

OTP is a set of Erlang libraries and design principles, and understanding it is crucial for building robust, fault-tolerant applications.

Has the candidate shown an ability to learn and adapt?

The tech industry is always evolving, so it's important for a developer to be able to keep up with new technologies and practices.

Does the candidate have experience with concurrent programming?

Erlang is a concurrent programming language, so experience in this area is highly beneficial.

Is the candidate able to communicate effectively?

Good communication skills are important for understanding project requirements and collaborating with team members.

Has the candidate demonstrated problem-solving skills during the interview?

Problem-solving skills are essential for a developer to troubleshoot and fix issues that may arise during coding.

Does the candidate have a solid understanding of Erlang R16B03-1?

This is crucial because the job position requires a deep knowledge of this specific version of Erlang.

Next 20 minutes

Specific Erlang R16B03-1 development questions

The next 20 minutes of the interview should attempt to focus more specifically on the development questions used, and the level of depth and skill the engineer possesses.

Describe the difference between hot and cold code loading in Erlang.

Hot code loading in Erlang allows for a new version of a module to be loaded and run without stopping the system. Cold code loading requires the system to be stopped before a new version of a module can be loaded.

What are the benefits of immutability in Erlang?

Immutability in Erlang eliminates the risks of state changes, making the code easier to understand and debug. It also allows for more efficient use of resources in concurrent and distributed systems.

How would you handle state in Erlang processes?

State in Erlang processes is handled by passing the state as an argument to the function that represents the process. The function can then return a new state as part of its result.

Describe the difference between synchronous and asynchronous message passing in Erlang.

In synchronous message passing, the sender waits for the receiver to receive the message. In asynchronous message passing, the sender does not wait and can continue with other tasks.

What is the role of the OTP framework in Erlang?

The OTP (Open Telecom Platform) framework in Erlang provides a set of libraries and tools that are used to build robust, scalable, and maintainable applications.

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The ideal back-end app developer

What you’re looking to see on the Erlang R16B03-1 engineer at this point.

At this point, the candidate should demonstrate proficiency in concurrent programming, fault-tolerance mechanisms and hot-swapping of running code. They should exhibit deep knowledge of Erlang syntax and OTP framework. Red flags include lack of hands-on experience or difficulty explaining complex concepts clearly.

Digging deeper

Code questions

These will help you see the candidate's real-world development capabilities with Erlang R16B03-1.

What does this simple Erlang code do?

io:format("Hello, World!~n", []).

This code prints the string 'Hello, World!' to the console. The '~n' is a newline character.

What will be the output of this Erlang code?

io:format("~p~n", [1+2*3]).

The output will be '7'. The code performs the arithmetic operation 1+2*3, where multiplication has higher precedence, so it's calculated first. The '~p' is a placeholder for the result, which is then printed to the console.

What does this Erlang code do?

lists:map(fun(X) -> X*X end, [1,2,3,4,5]).

This code squares each element in the list [1,2,3,4,5]. The 'fun' keyword is used to define an anonymous function that takes an argument 'X' and returns the square of 'X'. The 'lists:map' function applies this anonymous function to each element of the list.

What does this Erlang code do?

spawn(fun() -> io:format("Hello from a new process~n", []) end).

This code spawns a new process that prints 'Hello from a new process' to the console. The 'spawn' function is used to create a new process in Erlang.

What does this Erlang code do?

start() -> io:format("Hello from a module~n", []).

This code defines a module named 'test' with a single function 'start' that takes no arguments. The function prints 'Hello from a module' to the console. The '-export' directive makes the 'start' function available to other modules.

What will be the output of this Erlang code?

start() -> X = 5, Y = 10, Z = X + Y, io:format("~p~n", [Z]).

The output will be '15'. The code defines a module with a function that initializes two variables 'X' and 'Y' with values '5' and '10' respectively, adds them together to get 'Z', and then prints 'Z' to the console.

Wrap-up questions

Final candidate for Erlang R16B03-1 role questions

The final few interview questions for a Erlang R16B03-1 candidate should typically focus on a combination of technical skills, personal goals, growth potential, team dynamics, and company culture.

What are the challenges of programming in Erlang and how would you overcome them?

Challenges of programming in Erlang include the unfamiliar syntax and semantics, the difficulty of debugging concurrent programs, and the lack of libraries for certain tasks. These can be overcome by learning the language thoroughly, using tools like the Erlang debugger, and interfacing with other languages when necessary.

How would you handle a situation where a process in Erlang needs to maintain a large amount of state?

In such a situation, the state can be stored in an ETS (Erlang Term Storage) table or a database. This allows the state to be accessed and updated without having to pass it around between processes.

Describe the difference between process-oriented and object-oriented programming in Erlang.

In process-oriented programming, which is used in Erlang, the focus is on processes and the messages they exchange. In object-oriented programming, the focus is on objects and their interactions.

What are the key features of the Erlang programming language?

Key features of Erlang include support for concurrent programming, distribution, fault-tolerance, hot code loading, and a functional programming style.

How would you implement a distributed system in Erlang?

A distributed system in Erlang can be implemented using the built-in support for distribution. This includes the ability to spawn processes on remote nodes and send messages between processes on different nodes.

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Erlang R16B03-1 application related

Product Perfect's Erlang R16B03-1 development capabilities

Beyond hiring for your Erlang R16B03-1 engineering team, you may be in the market for additional help. Product Perfect provides seasoned expertise in Erlang R16B03-1 projects, and can engage in multiple capacities.