io:format("Hello, World!~n", [])..webp){kind=logo}
Ask the right questions to secure the right Erlang 22 talent among an increasingly shrinking pool of talent.
Erlang 22 is a general-purpose, concurrent, functional programming language and runtime system developed by Ericsson in the late 1980s to build robust telecommunication systems. It was named after Agner Krarup Erlang, a Danish mathematician known for his work in queueing theory. The language was open-sourced in 1998 and has since been used extensively for building massively scalable real-time systems with high availability requirements (source: "The History of Erlang", Armstrong et al., ACM SIGPLAN). Notable features of Erlang include its support for hot swapping, where code can be changed without stopping a system; lightweight processes; and built-in support for concurrency, distribution and fault tolerance. As per the official documentation from erlang.org, version 22 includes enhancements to the garbage collector as well as new features such as improved logging capabilities.
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.
Lists are used when the number of elements is unknown or can change, while tuples are used when the number of elements is known and fixed.
Erlang follows the 'let it crash' philosophy for error handling. It encourages the creation of supervision trees to manage and recover from errors.
Some advantages of using Erlang include its fault-tolerant nature, support for hot swapping, highly efficient garbage collection, and support for distributed computing.
Erlang uses a lightweight process concurrency model. It allows for the creation of thousands of processes that can run concurrently, with built-in support for communication and synchronization.
Erlang is primarily used for building scalable and maintainable applications. It is especially good for building distributed, fault-tolerant, soft real-time concurrent systems.
These skills are crucial for any programming role. They indicate that the candidate can effectively tackle complex problems and implement efficient solutions.
Erlang is a functional programming language. Comfort with functional programming paradigms indicates that the candidate can write clean, efficient, and maintainable Erlang code.
OTP is a crucial part of Erlang's ecosystem. Experience with OTP shows that the candidate can build complex, production-ready applications.
Erlang is known for its robust fault-tolerance capabilities. A candidate's ability to leverage these features shows a deep understanding of the language and its strengths.
Erlang is a language designed for concurrent programming. Experience in this area indicates that the candidate can effectively handle tasks that involve managing multiple processes at once.
This is crucial because it shows that the candidate has a strong foundation in Erlang 22 and can effectively write, debug, and optimize code.
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.
Erlang provides built-in primitives for building distributed systems. This can be done by creating multiple Erlang nodes and using message passing for communication between these nodes.
OTP (Open Telecom Platform) is a set of libraries and design principles in Erlang. It provides tools to build reliable and high-availability systems.
ETS (Erlang Term Storage) tables are in-memory databases provided by Erlang. They can store large amounts of data and provide constant time access.
In Erlang, servers can be implemented using the gen_server behaviour module. This provides a generic server functionality for implementing servers in a concurrent environment.
Tail recursion is a feature in Erlang where the recursive call is the last operation in the function. It is important because it allows the Erlang runtime system to reclaim memory used by the function call stack, making recursion more efficient.
At this point, a skilled Erlang 22 engineer should demonstrate proficiency in concurrent programming, fault tolerance, and distributed systems. They should also show experience with OTP design principles. Red flags would include difficulty explaining complex concepts or lack of practical experience.
io:format("Hello, World!~n", []).lists:map(fun(X) -> X*X end, [1,2,3,4,5]).lists:filter(fun(X) -> X rem 2 == 0 end, [1,2,3,4,5]).spawn(fun() -> timer:sleep(1000), io:format("Hello, World!~n", []) end).-module(my_module).
-export([start/0]).
start() -> io:format("Hello, World!~n", []).-module(my_module).
-export([factorial/1]).
factorial(0) -> 1;
factorial(N) when N > 0 -> N * factorial(N-1).The final few interview questions for a Erlang 22 candidate should typically focus on a combination of technical skills, personal goals, growth potential, team dynamics, and company culture.
Erlang provides a mechanism to set a timeout for a process. If the process does not finish within the specified time, it will be killed. This can be done using the after clause in receive statements.
Debugging in Erlang can be challenging due to its concurrent nature. Traditional debugging methods may not work well. Erlang provides a graphical debugger tool and also supports tracing for debugging.
Erlang supports hot code swapping natively. This can be done by loading the new version of the module using the code:load_file/1 function.
Mnesia is a distributed, soft real-time database management system written in Erlang. It provides high availability and partition tolerance features.
spawn creates a new process while spawn_link creates a new process and links it to the current process. If a process linked with spawn_link crashes, the current process will also be terminated.
Back-end App Developer
Front-end Web Developer
Full Stack Developer (Java)
Full Stack Developer (.Net)
Full Stack Developer (MEAN)
Full Stack Developer (MERN)
DevOps Engineer
Database Engineer (AzureSQL)
Database Engineer (Oracle)
Database Engineer (General)
Solution Architect (.NET)
Solution Architect (Java)
Solution Architect (Ruby)
Solution Architect (Python)
AI Engineer (Python)
Sr. AI Engineer (Python)
AI Strategist (Python)
Business Intelligence Engineer
Systems Analyst
Mainframe Developer (COBOL)
Mainframe Developer (General)