DocSend Software Engineer interview questions

Don't want to spoil their interview, but there were no LeetCode-style riddles. I had to do very simple things that I do all the time in Rails, like make endpoints, design classes, and so forth. If you normally copy-paste your company's code and make necessary changes so you don't have to write boilerplate, stop doing that for a bit before interviewing here. Lesson learned. The job posting didn't mention jQuery and I was asked a jQuery question, though the recruiter told me that I'd be asked about it in the technical interview a week beforehand so I should have been prepared.

* `word.txt` is the full set of words in the lexicon. You won't need to change this but feel free to look at it to get a sense of the words you'll be using. * `public/` houses the javascript and css. Note that jQuery is already included for you. * `views/` contains two Haml templates for the two main pages. * `lexicon.rb` is the base class that reads the words into memory. * `special_lexicon.rb` has some stubs for you to implement the anagrams, prefix, and word ladder lookups. * `site.rb` defines all of the routes and logic for our simple server. The main stubs are provided inside `special_lexicon.rb`. You can place all your code to solve the algorithmic problems inside that file, but you are welcome to modify `lexicon.rb` if you want to change any functionality in that class. In the process of updating the site to be a cool single page app as your final piece of this task you will also want to take a peek inside of `main.js` and `index.haml`. You can add or alter any markup in `index.haml` to make your life easier. `main.js` is where you'll want to add or alter the code in order to perform any requests needed to avoid page navigation. Of course, should the mood strike, feel free to update any styles on the page as well. Finally, please write a few quick comments for each lexicon method describing how you decided to solve the problem. In addition, make sure to leave comments in the JS where it makes sense. It's perfectly acceptable and encouraged to use the internet for help (after all, that's what you'll be doing on the job!), just make sure you cite any sources. Please make sure that you are commit regularly with thoughtful commit messages throughout the project. ## Resources You may find the following sites helpful for a basic overview of the libraries being used on the site. Deep knowledge isn't required. A quick overview augmented by some Google-fu should be more than enough. * [Sinatra]A micro web framework. * [Haml] Nice, clean HTML markup. * [Bundler] Application dependency management. ## Requirements * Simple, clean, easy to read, and easy to understand code (that goes for comments and commit messages as well!) * Efficient algorithmic implementations * It runs and produces the correct results * It does not throw exceptions or crash when given unexpected inputs You shouldn't need to know Ruby, Haml, or Sinatra particularly well to complete the task. We aren't looking for deep, idiomatic knowledge of any of those. ### Anagrams * You can find the anagram for marsipobranchiata * You do it in better than O(n) time ### Prefixed words * Find prefixes faster than O(n) time ### Word ladder * Non-lexicon start and end words should print something sensible * The word shortest possible ladder from chair -> table is found efficiently * One example ladder: chair -> charr -> chirr -> shirr -> shire -> spire -> spiry -> sairy -> saily -> sably -> sable -> table ## Deliverables Please send back a zip of the entire app, including: * The entire `.git/` directory so that we can look through your commit history. * All files needed to run the app. This should include any and all files you added or changed. Please _do not_ upload your app to a public repo. If you have trouble attaching the zip to your email, you can sign up for a free trial of DocSend to send your deliverable to us! ## Some Helpful Info ### Tradeoffs * You should treat everything case insensitively * Prioritize the speed of web requests over startup time * Feel free to trade memory for speed / algorithmic efficiency ### Definitions #### Anagram **Definition:** A rearranging of the letters of a word to form a new dictionary word, using each letter from the original word exactly once. For example, 'act' is an anagram for 'cat' but 'tca' is not. #### Word Ladder **Definition:** The shortest possible chain between two words where each step in the chain differs by only a single letter. The start and end words must be the same length. **Example:** cold -> cord -> card -> ward -> warm