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Contract Ruby On Rails Software Engineer was asked...January 27, 2012

Describe a routine which returns the set of integers in {1..100} divisible without remainder by 3 but not by 9.

12 Answers

(1..100).select { |x| x%3 == 0 && x%9 != 0

1) start from number = 3 Loop while(number <= 100) 2) display number 3) number = number+3, display number 4) number = number+6 Loop Less

put those integers into an array, pick every third element, out of which discard every third element. Less

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This was a pair programming session with a Ruby engineer. They allow you to use your own laptop which was great but you only get 30 minutes to finish the problem with working unit tests. I think they re-use this pair programming problem so I'm not going to divulge details here. But it wasn't a particularly hard problem, they just want you to see how you code and test. Do not forget to write unit tests! Ideally you would develop it in a TDD fashion.

2 Answers

I wrote failing unit tests to determine the API first and then kept writing code until the tests succeeded. Less

Do they expect use of rspec, minitest or just simple assert methods for tdd?

what is out put of: 1) a && b, 2) a ||= b, 3) a & b?

1 Answers

1) bigger value will be returned, 2) b is assigned to a if a is nil or false, 3) Boolean value will be returned based on the value of a and b(if any of a or b is nil or false false will be returned Less


What type of data structure would you use to implement auto-complete functionality where memory usage needs to be minimized?

1 Answers

Use a trie


experiencias pasadas, conocimientos, prueba tecnica muy basica

1 Answers

di un resumen de mi experiencia y conocimiento, la prueba tecnica era mas que todo teorica en la que consultaban conceptos basicos de desarrollo. Less

Sunflower Lab

They asked me that Do you know elastic search?

1 Answers

I answered , Elastic search is gem which is used to implement the search functionality. Less


If we have 8 same little balls, but one of them is less weight. How may times do we need to weigh them to define which ball is less weight?

1 Answers

6 times


Prueba tenica mediate plataforma online y segunda prueba tecnica compartiendo pantalla

1 Answers

realizando los ejercicios solicitados

Icreon Communications

Have you created any gem of yours?

1 Answers



How did you become a Ruby on Rails Developer?

1 Answers

I was a WordPress PHP developer at the time and I discovered that with Ruby on Rails you have more control over data flow and the Rails routing engine. (interview did not seem to understand what I meant by data flow). I explained from a data flow perspective that Rails allows for custom routes and custom routes with their own actions, unlike WordPress, which I was working with at the time. (Interviewing began wanting to debate me that you cannot compare one with the other). I answered I was not doing a compare and contrast, but walking him through how I went from PHP WordPress to being a Ruby on Rails developer. Less

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