Asking developers to build a battleship game from scratch is just misguided at best when you build and sell (free) HR Solutions as a business. How are those 2 related? You can really judge a company by their poor interviewing processes.

Complete waste of my time. Another one of those not interested in your abilities, experience or the type of engineer you are, or if you can write quality code. Take home challenge. My time is limited, so i timebox my effort. When I reached that limit I stopped, knowing that the functionality was not 100%, and that I needed to add more unit tests. Still my solution was satisfying SOLID principles, it was easily testable and extendible, had decent unit test coverage, it was good code. The only feedback I got was that one of the functions was not completely accurate. No feedback about better coding standards, or different patterns which I could use. No useful feedback… They give you a checklist… When submitting your solution, please review it to ensure: ● Has been submitted via a git repository ● It meets the requirements ● Has no bugs ● Contains unit tests ● Demonstrates you have considered readability, maintainability, testability and extensibility Your solution might be the best written and organized code, if you slightly misunderstood one requirement, it is an automatic FAIL. This is a take home challenge, so you cannot clarify requirements. Unless you are completely confident you understand what they are after and that you can satisfy everything 100% , you WILL waste your time.